CN105720816B - The control circuit of buck-boost type converter, control method and apply its buck-boost type converter - Google Patents

The control circuit of buck-boost type converter, control method and apply its buck-boost type converter Download PDF

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Publication number
CN105720816B
CN105720816B CN201610231969.9A CN201610231969A CN105720816B CN 105720816 B CN105720816 B CN 105720816B CN 201610231969 A CN201610231969 A CN 201610231969A CN 105720816 B CN105720816 B CN 105720816B
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signal
buck
current
boost type
thermal compensation
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CN105720816A (en
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罗迪
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Hangzhou Silergy Semiconductor Technology Ltd
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Hangzhou Silergy Semiconductor Technology Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/1566—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators with means for compensating against rapid load changes, e.g. with auxiliary current source, with dual mode control or with inductance variation

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses the control circuits and control method for buck-boost type converter, sample inductive current, and generate current sampling signal according to this；Control receives current sampling signal in each switch periods in the rise time section of inductive current；Inductive current peak moment to current switch period finish time is risen in inductive current, the maximum of current sampling signal is kept, sampled signal is generated with this；Inductive current peak is limited by the second reference signal of the maximum value information for characterizing inductive current so that excessive fluctuation will not occur for inductive current, also can be relatively reduced so as to the fluctuation of output voltage；Feedback control loop can carry out the duty cycle of adjusting switch device according to the Real-time Error information between the voltage signal of thermal compensation signal and characterization inductive current simultaneously, therefore, the dynamic responding speed of system is very fast, and shortening recovers again to the time needed for stable state to improve the dynamic responding speed, stability and reliability of system.

Description

The control circuit of buck-boost type converter, control method and apply its buck Code converter
Technical field
The present invention relates to field of switch power, more specifically to the control circuit for buck-boost type converter and Control method.
Background technology
Buck-boost type converter, such as four switch buck-boost type converters, due to the same phase of its input and output, switching loss Low, output voltage, which can rise, is widely used in the fields such as electric power, communication and electronic instrument the advantages that can dropping, to the excellent of its contactor Changing control strategy also becomes the hot spot of current research.
With reference to figure 1A, the functional block diagram of a buck-boost type converter is shown.The buck-boost type converter includes power stage 12 two parts of circuit 11 and driving circuits；Wherein, power stage circuit 11 receives input voltage vin, and is produced in output terminal Driving load since raw stable output voltage Vout；Driving circuits 12 are generating corresponding control and drive signal VG1, VG2, VG3And VG4, to control the on off state of 4 switching tubes in power stage circuit, accounted for by the conducting of adjusting switch pipe Sky is than so that output voltage Vout is maintained consistent with it is expected driving voltage Vref.
Here, power stage circuit 11 includes the first switch pipe SW1 being connected in series between input voltage vin and ground potential With the 3rd switching tube SW3；The second switch pipe SW2 and the 4th switching tube being connected in series between output voltage Vout and ground potential SW4；First end is connected to the public connecting end of first switch pipe SW1 and the 3rd switching tube SW3, and second end is connected to second switch The inductance L of the public connecting end of pipe SW2 and the 4th switching tube SW4.Power stage circuit 11 can also include being connected to input terminal Input capacitance and the output capacitance Co for being connected to output terminal.
The operation principle of buck-boost type converter shown in Figure 1A, control circuit and driving circuit 12 are according to input voltage The magnitude relationship of Vin and output voltage Vout control the operating mode of power stage circuit 11, when input voltage vin is more than output During voltage Vout, worked with decompression mode；When input voltage vin is less than output voltage Vout, work in a boost mode；When defeated When entering voltage Vin and output voltage Vout and being closer to, worked with buck-boost mode.
The control principle of buck-boost type converter shown in Figure 1A mainly in real time acquisition output voltage Vout, according to real-time Error and inductive current information between output voltage and desired output voltage generate corresponding control signal to adjust out The on off state and conducting dutycycle of pipe are closed, and then changes output voltage by changing input current.
But by this current control mode, when input voltage, output voltage change, operating mode is cut When changing, the fluctuation of inductive current is very big, and the fluctuation of output voltage is also very big, also, the dynamic responding speed of system it is relatively slow, it is necessary to Longer time could be recovered again to stable state.Meanwhile the working frequency of system can become larger, due to the numerical value of inductive current Also it is larger, therefore, easily cause audio-frequency noise.
With reference to figure 1B, the working waveform figure of the buck-boost type converter shown in Figure 1A is shown.Buck shown in Figure 1A Code converter can be accounted for by eliminating the error between thermal compensation signal Vcomp and the voltage signal VL for characterizing inductive current to adjust Empty ratio, so that inductive current iL can follow the track of thermal compensation signal Vcomp.But when buck-boost type converter work in it is disconnected During continuous operating mode (DCM), it is maintained in inductive current in zero time interval, such as in time interval t2, operation amplifier Device Gm2 is stopped, and does not calculate the error between thermal compensation signal Vcomp and the voltage signal VL for characterizing inductive current, that is, controls Loop can not be adjusted open according to the Real-time Error information between the voltage signal VL of thermal compensation signal Vcomp and characterization inductive current The duty cycle of device is closed, therefore, the dynamic responding speed of system is relatively slow, it is necessary to which longer time could be recovered again to stablizing shape State.On the other hand, in the prior art, when in light condition, in order to save energy consumption, it usually needs reduce in power stage circuit Switching tube switching frequency.Traditional underloading frequency reducing mode, after into energy saver mode, the switching tube in power stage circuit is not It turns on again, so as to reduce power consumption at light load, improves light-load efficiency.But in this way, switching frequency can dash forward Become, the fluctuation for causing output voltage is larger.
The content of the invention
In view of this, the control method it is an object of the invention to provide a kind of new buck-boost type converter and control Circuit, frequency hopping big with output voltage fluctuation when solving operating mode switching in the prior art and light condition, dynamic Low-response, efficiency is low and generates the technical problems such as audio-frequency noise.
The control method of buck-boost type converter according to one embodiment of the invention, for controlling a buck-boost type converter In switching tube on off state so that the output terminal of the buck-boost type converter output voltage maintain it is constant, including,
It samples the inductive current of the buck-boost type converter and generates a sampled signal according to this；In each switch periods It is interior, in the rise time section of the inductive current, the sampled signal and the inductive current direct proportionality；Institute It states inductive current and rises to inductive current peak moment to current switch period finish time, the sampled signal is maintained and institute State inductive current peak direct proportionality；
The difference of the desired output voltage of the output voltage and the buck-boost type converter is calculated to obtain the first mistake Difference signal, and computing is compensated to first error signal to obtain the first thermal compensation signal；
The difference of first thermal compensation signal and the sampled signal is calculated to obtain the second error signal, and to described Two error signals compensate computing to obtain the second thermal compensation signal；
Using second thermal compensation signal and the difference of a bias voltage as the 3rd thermal compensation signal；
According to second thermal compensation signal and a clock signal generation first control signal, the buck-boost type to be controlled to become The first switch pipe of parallel operation and the on off state of the 3rd switching tube；
According to the 3rd thermal compensation signal and clock signal generation second control signal, to control the buck-boost type The second switch pipe of converter and the on off state of the 4th switching tube.
Preferably, the method for generating second thermal compensation signal comprises the following steps：
Second reference signal of first thermal compensation signal and a characterization inductive current peak is compared；
When first thermal compensation signal is not less than second reference signal, first thermal compensation signal and described is calculated The difference of sampled signal, and computing is compensated to it to obtain second thermal compensation signal；
When first thermal compensation signal is less than second reference signal, calculates second reference signal and described adopt The difference of sample signal, and computing is compensated to it to obtain second thermal compensation signal.
Preferably, generate and comprise the following steps in the method for the first control signal and the second control signal：
The frequency of the clock signal is adjusted according to the average value of the inductive current.
Preferably, generate and comprise the following steps in the method for the first control signal and the second control signal：
The frequency of the clock signal is adjusted according to first thermal compensation signal.
Preferably, further include, adjusted according to the error amount between first thermal compensation signal and second reference signal Save the frequency of the clock signal.
Preferably, further include,
When first thermal compensation signal is less than second reference signal, according to first thermal compensation signal and described the Error amount between two reference signals adjusts the frequency of the clock signal；
When first thermal compensation signal is not less than second reference signal, the frequency of the clock signal maintains not Become.
Preferably, generate and comprise the following steps in the method for the first control signal and the second control signal：
The frequency of the clock signal is adjusted according to the error between the output voltage and the desired output voltage.
Preferably, the method for generating the sampled signal comprises the following steps：
The inductive current is sampled, and generates current sampling signal according to this；
Control receives the current sample letter in each switch periods in the rise time section of the inductive current Number；
Inductive current peak moment to current switch period finish time is risen in the inductive current, to the electric current The maximum of sampled signal is kept, and the sampled signal is generated with this.
The control circuit of buck-boost type converter according to one embodiment of the invention, for controlling a buck-boost type converter In switching tube on off state so that the output terminal of the buck-boost type converter output voltage maintain it is constant, including,
Circuit occurs for sampled signal, to sample the inductive current of the buck-boost type converter and one sampling of generation according to this Signal；In each switch periods, in the rise time section of the inductive current, the sampled signal and inductance electricity Flow direct proportionality；Inductive current peak moment to current switch period finish time, institute are risen in the inductive current Sampled signal is stated to be maintained and the inductive current peak direct proportionality；
First error calculation and compensation circuit, to calculate the expectation of the output voltage and the buck-boost type converter Difference between output voltage, and computing is compensated to it, to obtain the first thermal compensation signal；
Second error calculation and compensation circuit, to calculate the difference between first thermal compensation signal and the sampled signal Value, and computing is compensated to it, to obtain the second thermal compensation signal；
First compares and logic circuit, to according to second thermal compensation signal and a clock signal generation first control letter Number, to control the on off state of the first switch pipe of the buck-boost type converter and the 3rd switching tube；
Second compares and logic circuit, to be believed according to the 3rd thermal compensation signal and the second control of clock signal generation Number, to control the on off state of the second switch pipe of the buck-boost type converter and the 4th switching tube；The second compensation letter Number and a bias voltage difference as the 3rd thermal compensation signal.
Preferably, a selection circuit is further included, to receive first thermal compensation signal and a characterization inductive current Second reference signal of peak value, and the greater in the two is transferred to second error calculation and compensation circuit；
When first thermal compensation signal is not less than second reference signal, first thermal compensation signal and described is calculated The difference of sampled signal, and computing is compensated to it to obtain second thermal compensation signal；
When first thermal compensation signal is less than second reference signal, calculates second reference signal and described adopt The difference of sample signal, and computing is compensated to it to obtain second thermal compensation signal.
Preferably, frequency control circuit is further included, the clock is adjusted to the average value according to the inductive current The frequency of signal.
Preferably, the frequency control circuit includes ramp generator and a comparison circuit；
In each switch periods, in the ineffective time section of the clock signal, the ramp generator production Raw ramp voltage signal linear rise；
The average value of the inductive current is controlling the rate of rise of the ramp voltage signal；When the inductive current Average value increase when, the ramp signal the rate of rise increase；It is described oblique when the average value of the inductive current reduces The rate of rise of slope signal reduces；
The comparison circuit is comparing the ramp voltage signal received and a threshold voltage；When slope electricity When pressure signal rises to the threshold voltage, the clock signal becomes effective status；
The output signal of the comparison circuit is as the clock signal.
Preferably, the ramp generator includes the controllable current being connected in series between voltage source and ground potential Source and capacitance, the controllable switch being connected in parallel with the capacitance；
The on off state of the controllable switch is controlled by the clock signal；
The voltage signal of the public connecting end of the controllable current source and the capacitance is as the ramp voltage signal；
The output current of the controllable current source and the average value direct proportionality of the inductive current.
Preferably, frequency control circuit is further included, to according to the difference between the output voltage and desired output voltage Value adjusts the frequency of the clock signal.
Preferably, frequency control circuit is further included, to according to first thermal compensation signal and second reference signal Between difference adjust the frequency of the clock signal.
Preferably, the frequency control circuit includes current regulating circuit, ramp generator and a comparison circuit；
In each switch periods, in the ineffective time section of the clock signal, the ramp generator production Raw ramp voltage signal linear rise；
The current regulating circuit is adjusting the rate of rise of the ramp voltage signal；
The comparison circuit is comparing the ramp voltage signal received and a threshold voltage；When slope electricity When pressure signal rises to the threshold voltage, the clock signal becomes effective status；
The output signal of the comparison circuit is as the clock signal.
Preferably, the ramp generator include being connected in series in current source between voltage source and ground potential and Capacitance, the controllable switch being connected in parallel with the capacitance；
The on off state of the controllable switch is controlled by the clock signal；
Voltage signal on the public connecting end of the current source and the capacitance is as the ramp voltage signal；
The current regulating circuit is adjusting the charging current of the capacitance.
Preferably, the current regulating circuit is according to the mistake between first thermal compensation signal and second reference signal Difference adjusts the charging current of the capacitance.
Preferably, the current regulating circuit includes operational transconductance amplifier and single-way switch；
Two input terminals of the operational transconductance amplifier are received respectively according to first thermal compensation signal and described second Reference signal；
The single-way switch is connected to the output terminal of the operational transconductance amplifier and the current source and the capacitance Between public connecting end, the operational transconductance is flowed to only to allow the public connecting end of electric current from the current source and the capacitance The output terminal of amplifier.
Preferably, circuit, which occurs, for the sampled signal includes,
Current sampling circuit to sample the inductive current, and generates current sampling signal according to this；
Holding circuit to receive the current sampling signal, and protects the maximum of the current sampling signal It holds, the output signal of the holding circuit is as the sampled signal；
Sampling control circuit is connected between the current sampling circuit and the holding circuit, to control each In switch periods, the holding circuit receives the current sampling signal in the rise time section of the inductive current, The inductive current rises to inductive current peak moment to current switch period finish time, and the sampled signal is maintained institute State the maximum of current sampling signal.
According to the buck-boost type converter of one embodiment of the invention, including power stage circuit, any lifting described above The control circuit and driving circuit of die mould converter；
The first switch pipe and the 3rd that the power stage circuit includes being connected in series between input voltage and ground potential is opened Guan Guan；The second switch pipe and the 4th switching tube being connected in series between output voltage and ground potential；First end is connected to first The public connecting end of switching tube and the 3rd switching tube, second end are connected to the public connecting end of second switch pipe and the 4th switching tube Inductance；And it is connected to the output capacitance of output terminal；
The driving circuit generates corresponding drive signal according to first control signal and second control signal.According to this The buck-boost type converter of inventive embodiments, the working frequency of switching tube can in real time according to the variation of the working condition of system, Such as the size variation of the inductive current either size variation of the size variation of output voltage or the first thermal compensation signal, to carry out Adjusting control, so that inductive current is capable of the variation of system for tracking faster, such as the variation etc. of output loading.Work as output When load becomes light condition or when output voltage increases suddenly, the average value of inductive current reduces accordingly so that clock The frequency of signal CLK reduces accordingly, so as to which inductive current will not frequently change, will not generate larger fluctuation, output electricity Pressure will not generate big fluctuation accordingly；Meanwhile the peak value of inductive current can be by characterizing the maximum of the inductive current Second reference signal of value information is further limited so that excessive fluctuation will not occur for inductive current, so as to export electricity The fluctuation of pressure also can be relatively reduced；Control loop can be according between the voltage signal of thermal compensation signal and characterization inductive current simultaneously Real-time Error information carry out the duty cycle of adjusting switch device, therefore, the dynamic responding speed of system is very fast, and shortening recovers again The dynamic responding speed, stability and reliability of system are improved to the time needed for stable state；Meanwhile it also avoids rising Buck convertor is in light condition, caused by possibility the problem of audio-frequency noise.
Description of the drawings
Figure 1A show the functional block diagram of a buck-boost type converter；
Figure 1B show the working waveform figure of the buck-boost type converter shown in Figure 1A；
Fig. 2A show the functional block diagram of the control circuit of the buck-boost type converter according to first embodiment of the invention；
Fig. 2 B show the work of the control circuit of the buck-boost type converter of the foundation embodiment of the present invention shown in Fig. 2A Oscillogram；
Fig. 3 show the functional block diagram of the control circuit of the buck-boost type converter according to second embodiment of the invention；
Fig. 4 show the functional block diagram of the control circuit of the buck-boost type converter according to third embodiment of the invention；
Fig. 5 show the frequency control circuit in the control circuit according to the buck-boost type converter of one embodiment of the invention Functional block diagram；
Fig. 6 show the FREQUENCY CONTROL electricity in the control circuit according to the buck-boost type converter of another embodiment of the present invention The functional block diagram on road；
Fig. 7 show the flow chart of the control method of the buck-boost type converter according to one embodiment of the invention.
Specific embodiment
Several preferred embodiments of the present invention are described in detail below in conjunction with attached drawing, but the present invention is not restricted to These embodiments.The present invention covers any replacement, modification, equivalent method and side made in the spirit and scope of the present invention Case.In order to which the public is made to have thorough understanding to the present invention, it is described in detail in present invention below preferred embodiment specific thin Section, and description without these details can also understand the present invention completely for a person skilled in the art.
The present invention can be presented in a variety of manners, some of them example explained below.
With reference to figure 2A, the original of the control circuit 200 of buck-boost type converter according to first embodiment of the invention is shown Manage block diagram.According to the embodiment, control circuit 200 is driving the switching tube in the power stage circuit of buck-boost type converter On off state, so that the output voltage Vout of output terminal remains constant.
According to the embodiment, control circuit 200 includes circuits below structure：
Circuit 201 occurs for sampled signal, to sample the inductive current iL of the inductance L in buck-boost type converter and according to this Generate a sampled signal Vcs；In each switch periods, in the rise time section of inductive current iL, sampled signal Vcs with Inductive current iL direct proportionalities；At the end of inductive current iL rises to inductive current peak moment to current switch period It carves, sampled signal Vcs is maintained and the inductive current peak direct proportionality；
Here, circuit 201, which occurs, for sampled signal can be connected to the input terminal of power stage circuit or be connected to inductance L's One end or suitable position；
First error calculation and compensation circuit 202, to calculate output voltage Vout and the buck-boost type converter Difference between desired output voltage Vep, and computing is compensated to it, to obtain the first thermal compensation signal Vcomp1；Specifically, In some applications, direct sampling and outputting voltage Vout may be excessive because of voltage value, and to the selection band of circuit components It is inconvenient to come；It therefore, can be by voltage feedback circuit, for example, by being connected in series between the two outputs by resistance R1 and electricity The resistor voltage divider network of R2 compositions is hindered, to obtain the feedback signal VFB with output voltage Vout into certain proportional relationship indirectly； Then calculate feedback signal VFB and with corresponding the first reference voltages into the proportional relationship of desired output voltage Vep Difference between Vref1, and carry out compensation operation and obtain the first thermal compensation signal Vcomp1；Here, compensation operation can be that RC is mended Repay computing；
Second error calculation and compensation circuit 203, to calculate between the first thermal compensation signal Vcomp1 and sampled signal Vpk Difference, and computing is compensated to it, to obtain the second thermal compensation signal Vcomp2；Here, compensation operation can be that RC is compensated Computing；
First logic circuit 204 receives the second thermal compensation signal Vcomp2, with according to the second thermal compensation signal Vcomp2 and clock Signal CLK generates first control signal Vctrl1 to control the on off state of the first switch pipe of buck-boost type converter；
Second logic circuit 205 receives the 3rd thermal compensation signal Vcomp3, with according to the 3rd thermal compensation signal Vcomp3 and clock Signal CLK generates second control signal Vctrl2 to control the on off state of the second switch pipe of buck-boost type converter；
The difference of second thermal compensation signal Vcomp2 and a bias voltage is equal to the numerical value of the 3rd thermal compensation signal Vcomp3.
As a kind of specific implementation, the first error calculation and compensation circuit 202 can include error amplifier Gm1 and RC compensation circuits.Two input terminals of error amplifier Gm1 receive feedback signal VFB and the first benchmark electricity respectively Press Vref1；The RC compensation circuits that the resistance Rc1 and capacitance Cc1 being connected in series are formed are connected to error amplifier Gm1's Between output terminal and ground potential；The output voltage signal of the output terminal of error amplifier Gm1 is as the first thermal compensation signal Vcomp1。
Second error calculation and compensation circuit 203 can include error amplifier Gm2 and RC compensation circuit.Error Two input terminals of operational amplifier Gm2 receive the first thermal compensation signal Vcomp1 and sampled signal Vcs respectively；Resistance Rc2 and electricity Hold Cc2 to be connected in series between output terminal and the ground potential of error amplifier Gm2；The output of error amplifier Gm2 The output voltage signal at end is as the second thermal compensation signal Vcomp2.
The anode of bias voltage source Vbias is connected to the output terminal of error amplifier Gm2, and the output voltage of negative terminal is made For the 3rd thermal compensation signal Vcomp3.
Here, in 4 switching tubes of the power stage circuit of buck-boost type converter, first switch pipe SW1 and second switch Pipe SW2 is controlled tr tube, for example, can be mosfet transistor, the 3rd switching tube SW3 and the 4th switching tube SW4 can be Controlled tr tube, for example, can be mosfet transistor, or single-way switch pipe, for example, diode etc..First switch The on off state of pipe SW1 and the 3rd switching tube SW3 are complementary, the on off states of second switch pipe SW2 and the 4th switching tube SW4 And complementary.First control signal Vctrl1 is to control the turn-on and turn-off of first switch pipe SW1 to act, the second control letter Number Vctrl2 is controlling the turn-on and turn-off of second switch pipe SW2 to act.As the 3rd switching tube SW3 and the 4th switching tube SW4 For controlled tr tube when, with the control signals of first control signal Vctrl1 complementations come control the conducting of the 3rd switching tube SW3 and Shut-off acts, and with the control signals of second control signal Vctrl2 complementations the turn-on and turn-off of the 4th switching tube SW4 is controlled to move Make.
It can be any suitable sampling hold circuit that circuit 201, which occurs, for sampled signal.For example, it may be RC samplings are kept Circuit.
As a kind of embodiment, circuit 201, which occurs, for sampled signal can include circuits below structure：
Current sampling circuit to sample the inductive current iL, and generates current sampling signal according to this；
Holding circuit to receive the current sampling signal, and protects the maximum of the current sampling signal It holds, the output signal of the holding circuit is as the sampled signal Vcs；
Sampling control circuit is connected between the current sampling circuit and the holding circuit, to control each In switch periods, the holding circuit receives the current sampling signal in the rise time section of the inductive current, The inductive current rises to inductive current peak moment to current switch period finish time, and the sampled signal is maintained institute State the maximum of current sampling signal.First logic circuit 204 and the second logic circuit 205 can be any suitable logic electricity Road, to generate corresponding first control signal Vctrl1 according to the second thermal compensation signal Vcomp2 and the 3rd thermal compensation signal Vcomp3 With second control signal Vctrl2, since maintain output voltage Vout and desired output voltage Vep be consistent.
With reference to figure 2B, the control circuit of the buck-boost type converter of the foundation embodiment of the present invention shown in Fig. 2A is shown Working waveform figure.
The control circuit of buck-boost type converter according to the present embodiment introduces inductive current peak information by two mistakes Difference computes and compensates for the feedback control loop of circuit and two logic circuit compositions；Therefore, when output loading is undergone mutation or When input voltage, output voltage change, the peak value of inductive current can be limited by feedback control loop so that inductance Excessive fluctuation will not occur for electric current, also can be relatively reduced so as to the fluctuation of output voltage, and shortening recovers again to stable state The required time improves the dynamic responding speed of system and the stability of system and reliability.
Meanwhile feedback control loop can according to thermal compensation signal Vcomp1 with characterization inductive current sampled signal Vcs it Between Real-time Error information carry out the duty cycle of adjusting switch device.
Even if buck-boost type converter works in intermittent controlled pattern (DCM), since circuit 201 occurs for sampled signal to electricity The sampling of inducing current peak information is kept so that sampled signal is in each switch periods, in the rise time of inductive current iL In section, sampled signal Vcs and inductive current iL direct proportionalities；The inductive current peak moment is risen in inductive current iL To current switch period finish time, sampled signal Vcs is maintained and the inductive current peak direct proportionality.Computing is put Big device Gm2 is in running order always in entire switch periods, feedback control loop continuously according to thermal compensation signal Vcomp1 with Real-time Error information between sampled signal Vcs carrys out the duty cycle of adjusting switch device.Therefore, by transient recovery to stable state The required time further shortens, and improves the dynamic responding speed of system.With reference to figure 3, it show real according to the present invention second Apply the functional block diagram of the control circuit 300 of the buck-boost type converter of example.According to the embodiment, control circuit 300 is driving The on off state of switching tube in the power stage circuit of buck-boost type converter, so that the output voltage Vout of output terminal is maintained It is constant.
According to the embodiment, on the basis of the control circuit 200 of the foundation first embodiment disclosed in Fig. 2, control circuit 300 further include selection circuit 301, to receive the first thermal compensation signal Vcomp1 and one characterization the buck-boost type converter allowed Inductive current maximum value information the second reference signal Vref2, and the greater in the two is transferred to the second error meter It calculates and compensation circuit 203.
When the first thermal compensation signal Vcomp1 is not less than the second reference signal Vref2, the first thermal compensation signal is calculated The difference of Vcomp1 and sampled signal Vpk, and computing is compensated to it to obtain the second thermal compensation signal Vcomp2；
When the first thermal compensation signal Vcomp1 is less than the second reference signal Vref2, the second reference signal Vref2 is calculated With the difference of sampled signal Vpk, and computing is compensated to it to obtain the second thermal compensation signal Vcomp2.
Here, selection circuit 301 can be with any suitable auctioneering circuit, and realization method can be any known Or unknown realization method, be no longer illustrated herein.
The control circuit of buck-boost type converter according to the present embodiment introduces inductive current peak information by two mistakes Difference computes and compensates for the feedback control loop of circuit and two logic circuit compositions；Therefore, when output loading is undergone mutation or When input voltage, output voltage change, the peak value of inductive current can be believed by characterizing the maximum of the inductive current Second reference signal Vref2 of breath is further limited so that excessive fluctuation will not occur for inductive current, so as to export electricity The fluctuation of pressure also can be relatively reduced, shortens and recovers the dynamic response for the time needed for stable state, improving system speed again The stability and reliability of degree and system.Meanwhile feedback control loop is continuously according to thermal compensation signal Vcomp1 and sampled signal Vcs Between Real-time Error information carry out the duty cycle of adjusting switch device.Therefore, as the time needed for transient recovery to stable state Further shorten, improve the dynamic responding speed of system.With reference to figure 4, the lifting according to third embodiment of the invention is shown The functional block diagram of the control circuit 400 of die mould converter.According to the embodiment, control circuit 400 is driving buck-boost type to become The on off state of switching tube in the power stage circuit of parallel operation, so that the output voltage Vout of output terminal remains constant.
In this embodiment, on the basis of the control circuit 200 shown in Fig. 2 according to first embodiment of the invention, control Circuit 400 processed further includes frequency control circuit 401, to generate clock signal clk, since adjust buck-boost type conversion Device, i.e., the working frequency of four switching tubes.
Clock signal clk is the pulse signal of the upper frequency with certain duty cycle.Under normal conditions, clock signal The frequency of CLK is fixed.In this embodiment, the frequency of clock signal clk can be according to the work of the buck-boost type converter The variation for making state is adjusted in real time, preferably to adapt to the working condition of the buck-boost type converter, improves response speed With the stability of system.In normal operating conditions, the frequency maintenance of clock signal clk is basically unchanged；And when system is in different During normal working condition, for example, output loading becomes light condition or when output voltage becomes larger suddenly, the frequency of clock signal clk Rate is reduced accordingly according to the working condition of system.
The variation of the working condition of buck-boost type converter can be by information such as output voltage or inductive currents Monitoring obtains indirectly, and therefore, the frequency of clock signal clk can be according to the variation to output voltage or inductive current come between Connect adjustment.
By way of reducing working frequency so that when output loading is in light condition, the switching frequency of switching tube Decline, so as to which inductive current iL will not be fluctuated frequently, and fluctuation will not be excessive.Meanwhile also avoid buck-boost type conversion When device is operated in discontinuous operating mode (DCM), caused by possibility the problem of audio-frequency noise.
With reference to figure 5, the frequency control showing in the control circuit according to the buck-boost type converter of one embodiment of the invention The functional block diagram of circuit processed.According to the embodiment, frequency control circuit 500 to generate clock signal clk, since adjust described in The working frequency of buck-boost type converter, i.e., the working frequency of four switching tubes.
In this embodiment, frequency being averaged according to inductive current for the clock signal clk that frequency control circuit 500 generates Value is adjusted.
A kind of realization method of frequency control circuit 500 is specific as follows：
Frequency control circuit 500 includes ramp signal generating circuit 505 and comparison circuit 504；Wherein ramp signal generates Circuit 505 in the ineffective time section in each switch periods of clock signal clk generating a numerical value and inductive current Average value direct proportionality ramp signal；
Comparison circuit 504 receives the ramp signal and a corresponding threshold signal, and the comparative result of the two is believed as clock Number CLK.
Specifically, ramp signal generating circuit 505 can include controllable current source 501, capacitance 502 and controllable switch 503.
Wherein, controllable current source 501 and capacitance 502 are connected in series between voltage source and ground potential；Controllable switch and electricity Hold 502 to be connected in parallel；Ramp voltage signal V on the points of common connection of controllable current source 501 and capacitance 502RAMPWith threshold value electricity Press VTHIt is respectively connected to two input terminals of comparison circuit 504；The output signal of the output terminal of comparison circuit 504 is believed as clock Number CLK.
The size of the output current of controllable current source 501 by inductive current average value iLavgControl is adjusted.Inductance The average value i of electric currentLavgIt can be obtained by a variety of realization methods.For example, real-time sampling flows through the inductive current iL of inductance L, And pass through a low-pass filter and inductive current is filtered to obtain the average value i of characterization inductive currentLavgThe voltage of information Signal.
The turn-on and turn-off state of controllable switch 503 is controlled by clock signal clk.When clock signal clk is effective When, controllable switch 503 is closed, and the voltage of capacitance 502 discharges, and the voltage of capacitance 502 declines；When clock signal clk is nothing During effect, controllable switch 503 disconnects, and the output current of controllable current source 501 charges to capacitance 502, the pressure-wire of capacitance 502 Property rise.
Comparison circuit 504, such as can be comparator circuit, to compare ramp signal received and one accordingly Threshold signal, as ramp voltage signal VRAMPRise to threshold voltage VTHWhen, clock signal clk becomes effective status, that is, maintains For high level state；And as ramp signal VRAMPLess than threshold voltage VTHWhen, clock signal clk becomes disarmed state, that is, maintains For low level state.
Pass through the producing method of above-mentioned clock signal so that the working frequency of switching tube can be in real time according to inductive current Control is adjusted in size variation, so that inductive current is capable of the variation of system for tracking faster, such as output loading Variation etc..When output loading becomes light condition or when output voltage increases suddenly, the average value i of inductive currentLavgPhase The reduction answered so that the frequency of clock signal clk reduces accordingly, so as to which inductive current will not frequently change, will not generate Larger fluctuation, output voltage will not generate big fluctuation accordingly, improve dynamic corresponding speed, the stability of system with And reliability.Meanwhile also avoid buck-boost type converter in light condition may caused by audio-frequency noise the problem of.
With reference to figure 6, the frequency showing in the control circuit according to the buck-boost type converter of another embodiment of the present invention The functional block diagram of control circuit.According to the embodiment, frequency control circuit 600 to generate clock signal clk, since adjust institute State the working frequency of buck-boost type converter, i.e., the working frequency of four switching tubes.
In this embodiment, the frequency for the clock signal clk that frequency control circuit 600 generates is according to current output voltage Control information between Vout and desired output voltage Vep is adjusted.When the control information is not less than a predetermined threshold value, The frequency of clock signal clk remains unchanged；And when the control information is less than the predetermined threshold value, such as output loading is in underloading When state or output voltage become larger suddenly, the frequency of clock signal clk is according to current output voltage Vout and desired output electricity Control information between pressure and reduce accordingly.
Here, which can be the second reference signal Vref2 of the maximum value information for characterizing the inductive current.
A kind of realization method of frequency control circuit 600 is specific as follows：
Frequency control circuit 600 includes current regulating circuit 601, ramp generator 602 and comparison circuit 603.
Wherein, ramp signal generating circuit 602 is to the ineffective time area in each switch periods of clock signal clk Interior generation one has the ramp signal V of certain rate of riseRAMP；
Current regulating circuit 601 to according to the control information between current output voltage Vout and desired output voltage come Adjust the numerical value of the rate of rise of the ramp signal；
Comparison circuit 603 receives ramp signal VRAMPWith corresponding threshold voltage VTH, the comparative result of the two as when Clock signal CLK.
Specifically, ramp signal generating circuit 602 can include current source 603, capacitance 604 and controllable switch 605.
Wherein, current source 603 and capacitance 604 are connected in series between voltage source and ground potential；Controllable switch 605 and capacitance 604 are connected in parallel；Ramp voltage signal V on the points of common connection of current source 603 and capacitance 604RAMPWith threshold voltage VTHPoint Two input terminals of comparison circuit 603 are not connected to.
Current regulating circuit 601 is adjusted according to the control information between current output voltage Vout and desired output voltage Flow to the size of the charging current of capacitance 604, since change ramp voltage signal VRAMPThe rate of rise.
The turn-on and turn-off state of controllable switch 605 is controlled by clock signal clk.When clock signal clk is effective When, controllable switch 605 is closed, and the voltage of capacitance 604 discharges, and the voltage of capacitance 604 declines；When clock signal clk is nothing During effect state, controllable switch 605 disconnects, output current and the formed adjusting electric current one of current regulating circuit 601 of current source 603 It rises and charges to capacitance 502, the voltage linear of capacitance 502 rises.
Preferably, the difference of the adjusting electric current generated using the output current of current source 603 with current regulating circuit 601 It charges to capacitance 502 so that the voltage linear of capacitance 502 rises.
Comparison circuit 603, such as can be comparator circuit, to compare ramp signal received and one accordingly Threshold voltage, when ramp voltage signal rises to the threshold voltage, clock signal clk becomes effective status, that is, is maintained high Level state；And when ramp voltage signal is less than the threshold voltage, clock signal clk becomes disarmed state, that is, is maintained low Level state.
The output signal of the output terminal of comparison circuit 603 is as clock signal clk.
Here, the variation of the numerical value for the adjusting electric current that current regulating circuit 601 is generated is so that the rising of ramp signal is oblique Rate changes, and rises to time span needed for the threshold signal so as to change ramp signal so that clock signal clk is opened The corresponding variation of cycle generation is closed, i.e. the frequency of clock signal clk changes.
A kind of realization method of current regulating circuit 601 is specific as follows：
Current regulating circuit 601 includes an operational transconductance amplifier 606 and a single-way switch 607；Wherein, operational transconductance is put Two input terminals of big device 606 receive the error letter that can be characterized between current output voltage Vout and desired output voltage respectively The second reference signal Vref2 of first thermal compensation signal Vcomp1 of breath and the maximum value information of the characterization inductive current, output End is connected to the public connecting end of current source 603 and capacitance 604 by single-way switch 607.The output of operational transconductance amplifier 606 Electric current is as adjusting electric current.Single-way switch 607 only allows electric current to flow to the output of operational transconductance amplifier 606 from current source 603 End.Single-way switch 607 can be diode, and cathode is connected to the output terminal of operational transconductance amplifier 606, and anode is connected to electricity Stream source 603 and the public connecting end of capacitance 604.Therefore, when clock signal clk is disarmed state, controllable switch 605 disconnects, The difference of the adjusting electric current generated using the output current of current source 603 with current regulating circuit 601 fills capacitance 502 Electricity.When output voltage Vout changes, the first thermal compensation signal Vcomp1 changes accordingly, and then adjusts the number of electric current Value also changes, and so as to which the numerical value of the charging current of capacitance 604 can change accordingly, the rate of rise of ramp signal becomes Change, time span needed for the threshold signal is risen to so as to change ramp signal so that the switch periods hair of clock signal clk Raw corresponding variation, the i.e. frequency of clock signal clk change.
Those skilled in the art are it is known that the voltage signal either comparison operation between current signal or error fortune It calculates, in order to make component can be with the smaller device of selected as parameter, voltage signal or current signal can be with one therewith into just The signal of proportionate relationship substitutes.Therefore, in embodiment according to the invention, voltage signal or current signal can also sample The mode of aforementioned proportion, for example, the signals such as output voltage Vout, the first thermal compensation signal Vcomp1, charging current.
Preferably, can also increase by a resistor voltage divider network to divide the first thermal compensation signal Vcomp1, to obtain one There is identical AC compounent with the first thermal compensation signal Vcomp1, and DC component and the first thermal compensation signal Vcomp1 are in direct ratio The compensation voltage signal Vc of relation.Correspondingly, characterize the second reference signal Vref2 of the maximum value information of the inductive current It is arranged to corresponding ratio.
A kind of realization method can be：
In former RC compensation circuits, on the basis of resistance Rc1 and capacitance Cc, increase between resistance Rc1 and capacitance Cc1 The voltage signal of the public connecting end of resistance Rc2, resistance Rc1 and resistance Rc2 is transferred to frequency as compensation voltage signal Vc Control circuit 600,500 etc..
Above to the circuit structure of control circuit and control original of the buck-boost type converter according to various embodiments of the present invention Reason is described in detail.The control circuit of new buck-boost type converter can be overlapped mutually to form between each embodiment. For example, the frequency control circuit 500 and 600 shown in Fig. 5 and Fig. 6 can also be respectively suitable for the revealed bucks of Fig. 2 and Fig. 3 In the control circuit 200 and 300 of code converter.
Pass through the producing method of above-mentioned clock signal so that the working frequency of switching tube can be in real time according to inductive current Control is adjusted in size variation, so that inductive current is capable of the variation of system for tracking faster, such as output loading Variation etc..When output loading becomes light condition or when output voltage increases suddenly, the average value of inductive current is corresponding Reduce so that the frequency of clock signal clk reduces accordingly, so as to which inductive current will not frequently change, will not generate larger Fluctuation, output voltage will not generate big fluctuation accordingly；Meanwhile the peak value of inductive current can be by characterizing the electricity Second reference signal of the maximum value information of inducing current is further limited so that excessive ripple will not occur for inductive current It is dynamic, also can be relatively reduced so as to the fluctuation of output voltage, shortening recovers to improve system to the time needed for stable state again Dynamic responding speed, stability and reliability；Meanwhile buck-boost type converter is also avoided in light condition, it may The problem of caused audio-frequency noise.
Embodiment according to the invention also reveals a kind of buck-boost type converter of four new switches.Buck-boost type becomes Parallel operation includes power stage circuit, the control circuit and driving circuit of the revealed any buck-boost type converters of Fig. 2-Fig. 6.
In 4 switching tubes in power stage circuit, first switch pipe SW1 and second switch pipe SW2 are controlled tr tube, example Such as, it can be mosfet transistor, the 3rd switching tube SW3 and the 4th switching tube SW4 can be controlled tr tube, for example, can be with For mosfet transistor, or single-way switch pipe, for example, diode etc..First switch pipe SW1 and the 3rd switching tube SW3 On off state be complementary, the on off state of second switch pipe SW2 and the 4th switching tube SW4 is also complementary.First control Signal Vctrl1 is to control the turn-on and turn-off of first switch pipe SW1 to act, and second control signal Vctrl2 is controlling the The turn-on and turn-off action of two switching tube SW2.When the 3rd switching tube SW3 and the 4th switching tube SW4 is controlled tr tube, with the The control signal of one control signal Vctrl1 complementations come control the turn-on and turn-off of the 3rd switching tube SW3 act, with second control The control signal of signal Vctrl2 complementations come control the turn-on and turn-off of the 4th switching tube SW4 act.
Driving circuit generates corresponding driving letter according to first control signal Vctrl1 and second control signal Vctrl2 Number.When power stage circuit is synchronized model power stage circuit, driving circuit generation drive signal VG1,VG2, VG3And VG4To drive respectively Move the switch motion of 4 switching tubes.When power stage circuit is non-synchronous type power stage circuit, driving circuit generation drive signal VG1And VG2, to respectively drive the switch motion of switching tube SW1 and SW2.
According to the buck-boost type converter of the embodiment of the present invention, the working frequency of switching tube can be in real time according to the work of system Make the variation of state, such as the size variation either size variation of output voltage or the first thermal compensation signal of inductive current is big Small variation, control is adjusted, so that inductive current is capable of the variation of system for tracking faster, such as output loading Variation etc..When output loading becomes light condition or when output voltage increases suddenly, the average value of inductive current is corresponding Reduce so that the frequency of clock signal clk reduces accordingly, so as to which inductive current will not frequently change, will not generate larger Fluctuation, output voltage will not generate big fluctuation accordingly；Meanwhile the peak value of inductive current can be by characterizing the electricity Second reference signal of the maximum value information of inducing current is further limited so that excessive ripple will not occur for inductive current It is dynamic, also can be relatively reduced so as to the fluctuation of output voltage, shortening recovers to improve system to the time needed for stable state again Dynamic responding speed, stability and reliability；Feedback control loop is continuously according between thermal compensation signal and sampled signal Real-time Error information carrys out the duty cycle of adjusting switch device.Therefore, it is further as the time needed for transient recovery to stable state Shorten, improve the dynamic responding speed of system.Meanwhile buck-boost type converter is also avoided in light condition, Ke Nengyin The problem of audio-frequency noise risen.
With reference to figure 7, the flow chart of the control method of the buck-boost type converter of foundation one embodiment of the invention is shown, is used In the on off state for controlling the switching tube in a buck-boost type converter, so that the output terminal of the buck-boost type converter Output voltage remains constant.
The control method of the buck-boost type converter comprises the following steps：
S701：It samples the inductive current of the buck-boost type converter and generates a sampled signal according to this；
In each switch periods, in the rise time section of the inductive current, the sampled signal and the electricity Inducing current direct proportionality；At the end of the inductive current rises to inductive current peak moment to current switch period It carves, the sampled signal is maintained and the inductive current peak direct proportionality；
S702：The difference of the desired output voltage of the output voltage and the buck-boost type converter is calculated to obtain One error signal, and computing is compensated to first error signal to obtain the first thermal compensation signal；
S703：The difference of first thermal compensation signal and the sampled signal is calculated to obtain the second error signal, and it is right Second error signal compensates computing to obtain the second thermal compensation signal；
S704：Using second thermal compensation signal and the difference of a bias voltage as the 3rd thermal compensation signal；
S705：According to second thermal compensation signal and a clock signal generation first control signal, to control the lifting The first switch pipe of die mould converter and the on off state of the 3rd switching tube；
S706：According to the 3rd thermal compensation signal and clock signal generation second control signal, to control the liter The second switch pipe of buck convertor and the on off state of the 4th switching tube.The buck-boost type converter of foundation the present embodiment Control method introduces inductive current peak information by feedback control loop；Therefore, when output loading is undergone mutation or defeated Enter voltage, when output voltage changes, the peak value of inductive current can be limited by feedback control loop so that inductance electricity Excessive fluctuation will not occur for stream, also can be relatively reduced so as to the fluctuation of output voltage, and shortening recovers again to stable state institute The time needed, improve the dynamic responding speed of system and the stability of system and reliability.
The control method of buck-boost type converter according to the embodiment of the present invention, the method for generating the second thermal compensation signal can be with Comprise the following steps：
Second reference signal of first thermal compensation signal and the maximum value information of a characterization inductive current is carried out Compare；
When first thermal compensation signal is not less than second reference signal, first thermal compensation signal and described is calculated The difference of sampled signal, and computing is compensated to it to obtain second thermal compensation signal；
When first thermal compensation signal is less than second reference signal, calculates second reference signal and described adopt The difference of sample signal, and computing is compensated to it to obtain second thermal compensation signal.
By this control method, while inductive current peak information is introduced by feedback control loop, further The second reference signal of maximum value information by characterizing the inductive current limit inductive current peak so that inductance electricity Excessive fluctuation will not occur for stream, also can be relatively reduced so as to the fluctuation of output voltage, and shortening recovers again to stable state institute The time needed, improve the dynamic responding speed of system and the stability of system and reliability.
The control method of buck-boost type converter according to the embodiment of the present invention generates first control signal and the second control It may comprise steps of in the method for signal：
The frequency of the clock signal, i.e., the working frequency of 4 switching tubes are adjusted according to the average value of inductive current.Example Such as, when the load of the output terminal of the buck-boost type converter is light condition, the work of the buck-boost type converter is reduced Working frequency.
Can control be adjusted according to the size variation of inductive current in real time in the working frequency of switching tube, so that electric Inducing current is capable of the variation of system for tracking faster, such as the variation etc. of output loading.When output loading becomes light condition, Or output voltage, when increasing suddenly, the average value of inductive current reduces accordingly so that the frequency of clock signal clk is corresponding Reduce, so as to which inductive current will not frequently change, larger fluctuation will not be generated, output voltage will not generate greatly accordingly Fluctuation；Shorten and recover to improve the dynamic responding speed of system, stability and can to the time needed for stable state again By property；Meanwhile buck-boost type converter is also avoided in light condition, caused by possibility the problem of audio-frequency noise.
The control method of buck-boost type converter according to another embodiment of the present invention generates first control signal and second It may comprise steps of in the method for control signal：
The frequency of the clock signal, i.e., the working frequency of 4 switching tubes are adjusted according to first thermal compensation signal.Example Such as, when the load of the output terminal of the buck-boost type converter is light condition, the work of the buck-boost type converter is reduced Working frequency.
It preferably, can be according to the second base of first thermal compensation signal and the maximum value information for characterizing the inductive current Error amount between calibration signal adjusts the working frequency of the clock signal.
When first thermal compensation signal is not less than second reference signal, the working frequency of the clock signal maintains It is constant；
When first thermal compensation signal is less than second reference signal, according to first thermal compensation signal and characterization institute The error amount between the second reference signal of the maximum value information of inductive current is stated to reduce the working frequency of the clock signal.
The control method of buck-boost type converter according to the embodiment of the present invention, generating the method for the sampled signal includes Following steps：
The inductive current is sampled, and generates current sampling signal according to this；
Control receives the current sample letter in each switch periods in the rise time section of the inductive current Number；
Inductive current peak moment to current switch period finish time is risen in the inductive current, to the electric current The maximum of sampled signal is kept, and the sampled signal is generated with this.Buck-boost type according to the embodiment of the present invention converts The control method of device, the working frequency of switching tube can be in real time according to the variations of the working condition of system, such as inductive current The size variation either size variation of the size variation of output voltage or the first thermal compensation signal, control is adjusted, so as to Enable the variation of inductive current system for tracking faster, such as the variation etc. of output loading.When output loading becomes underloading During state or when output voltage increases suddenly, the average value of inductive current reduces accordingly so that the frequency of clock signal clk Rate reduces accordingly, will not frequently change so as to inductive current, will not generate larger fluctuation, and output voltage is accordingly not yet Big fluctuation can be generated；Meanwhile the peak value of inductive current can pass through the second of the maximum value information for characterizing the inductive current Reference signal is further limited so that excessive fluctuation will not occur for inductive current, also can so as to the fluctuation of output voltage It is relatively reduced, shorten recover again to the time needed for stable state improve the dynamic responding speed of system, stability and Reliability；Meanwhile buck-boost type converter is also avoided in light condition, caused by possibility the problem of audio-frequency noise.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation In any this actual relation or order.Moreover, term " comprising ", "comprising" or its any other variant are intended to Non-exclusive inclusion, so that process, method, article or equipment including a series of elements not only will including those Element, but also including other elements that are not explicitly listed or further include as this process, method, article or equipment Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that Also there are other identical elements in process, method, article or equipment including the element.
According to the embodiment of the present invention as described above, these embodiments are there is no all details of detailed descriptionthe, also not It is only the specific embodiment to limit the invention.Obviously, as described above, can make many modifications and variations.This explanation Book is chosen and specifically describes these embodiments, is in order to preferably explain the principle of the present invention and practical application, so that affiliated Technical field technical staff can be used using modification of the invention and on the basis of the present invention well.The present invention is only by right The limitation of claim and its four corner and equivalent.

Claims (21)

1. a kind of control method of buck-boost type converter, for controlling the switch shape of the switching tube in a buck-boost type converter State, so that the output voltage of the output terminal of the buck-boost type converter remains constant, including,
It samples the inductive current of the buck-boost type converter and generates a sampled signal according to this；In each switch periods, In the rise time section of the inductive current, the sampled signal and the inductive current direct proportionality；In the electricity Inducing current rises to inductive current peak moment to current switch period finish time, and the sampled signal is maintained and the electricity Inducing current peak value direct proportionality；
The difference of the desired output voltage of the output voltage and the buck-boost type converter is calculated to obtain the first error letter Number, and computing is compensated to first error signal to obtain the first thermal compensation signal；
The difference of first thermal compensation signal and the sampled signal is calculated to obtain the second error signal, and is missed to described second Difference signal compensates computing to obtain the second thermal compensation signal；
Using second thermal compensation signal and the difference of a bias voltage as the 3rd thermal compensation signal；
According to second thermal compensation signal and a clock signal generation first control signal, to control the buck-boost type converter First switch pipe and the 3rd switching tube on off state；
According to the 3rd thermal compensation signal and clock signal generation second control signal, the buck-boost type to be controlled to convert The second switch pipe of device and the on off state of the 4th switching tube.
2. the control method of buck-boost type converter according to claim 1, which is characterized in that generation second compensation The method of signal comprises the following steps：
Second reference signal of first thermal compensation signal and a characterization inductive current peak is compared；
When first thermal compensation signal is not less than second reference signal, first thermal compensation signal and the sampling are calculated The difference of signal, and computing is compensated to it to obtain second thermal compensation signal；
When first thermal compensation signal is less than second reference signal, second reference signal and the sampling letter are calculated Number difference, and computing is compensated to it to obtain second thermal compensation signal.
3. the control method of buck-boost type converter according to claim 1, which is characterized in that generation first control Comprise the following steps in the method for signal and the second control signal：
The frequency of the clock signal is adjusted according to the average value of the inductive current.
4. the control method of buck-boost type converter according to claim 2, which is characterized in that generation first control Comprise the following steps in the method for signal and the second control signal：
The frequency of the clock signal is adjusted according to first thermal compensation signal.
5. the control method of buck-boost type converter according to claim 4, which is characterized in that further include, according to described Error amount between first thermal compensation signal and second reference signal adjusts the frequency of the clock signal.
6. the control method of buck-boost type converter according to claim 5, which is characterized in that it further includes,
When first thermal compensation signal is less than second reference signal, according to first thermal compensation signal and second base Error amount between calibration signal adjusts the frequency of the clock signal；
When first thermal compensation signal is not less than second reference signal, the frequency of the clock signal remains unchanged.
7. the control method of buck-boost type converter according to claim 1, which is characterized in that generation first control Comprise the following steps in the method for signal and the second control signal：
The frequency of the clock signal is adjusted according to the error between the output voltage and the desired output voltage.
8. the control method of buck-boost type converter according to claim 1, which is characterized in that generate the sampled signal Method comprise the following steps：
The inductive current is sampled, and generates current sampling signal according to this；
Control receives the current sampling signal in each switch periods in the rise time section of the inductive current；
Inductive current peak moment to current switch period finish time is risen in the inductive current, to the current sample The maximum of signal is kept, and the sampled signal is generated with this.
9. a kind of control circuit of buck-boost type converter, for controlling the switch shape of the switching tube in a buck-boost type converter State, so that the output voltage of the output terminal of the buck-boost type converter remains constant, including,
Circuit occurs for sampled signal, to sample the inductive current of the buck-boost type converter and one sampling letter of generation according to this Number；In each switch periods, in the rise time section of the inductive current, the sampled signal and the inductive current Direct proportionality；The inductive current peak moment is risen to current switch period finish time in the inductive current, it is described Sampled signal is maintained and the inductive current peak direct proportionality；
First error calculation and compensation circuit, to calculate the desired output of the output voltage and the buck-boost type converter Difference between voltage, and computing is compensated to it, to obtain the first thermal compensation signal；
Second error calculation and compensation circuit, to calculate the difference between first thermal compensation signal and the sampled signal, And computing is compensated to it, to obtain the second thermal compensation signal；
First compares and logic circuit, to according to second thermal compensation signal and a clock signal generation first control signal, To control the on off state of the first switch pipe of the buck-boost type converter and the 3rd switching tube；
Second compares and logic circuit, to generate second control signal according to the 3rd thermal compensation signal and the clock signal, with Control the second switch pipe of the buck-boost type converter and the on off state of the 4th switching tube；Second thermal compensation signal and one The difference of bias voltage is as the 3rd thermal compensation signal.
10. the control circuit of buck-boost type converter according to claim 9, which is characterized in that further include selection electricity Road, to receive the second reference signal of first thermal compensation signal and a characterization inductive current peak, and will be in the two The greater be transferred to second error calculation and compensation circuit；
When first thermal compensation signal is not less than second reference signal, first thermal compensation signal and the sampling are calculated The difference of signal, and computing is compensated to it to obtain second thermal compensation signal；
When first thermal compensation signal is less than second reference signal, second reference signal and the sampling letter are calculated Number difference, and computing is compensated to it to obtain second thermal compensation signal.
11. the control circuit of buck-boost type converter according to claim 9, which is characterized in that further include FREQUENCY CONTROL Circuit adjusts the frequency of the clock signal to the average value according to the inductive current.
12. the control circuit of buck-boost type converter according to claim 11, which is characterized in that the FREQUENCY CONTROL electricity Road includes ramp generator and a comparison circuit；
In each switch periods, in the ineffective time section of the clock signal, what the ramp generator generated Ramp voltage signal linear rise；
The average value of the inductive current is controlling the rate of rise of the ramp voltage signal；When putting down for the inductive current When average increases, the rate of rise increase of the ramp signal；When the average value of the inductive current reduces, the slope letter Number the rate of rise reduce；
The comparison circuit is comparing the ramp voltage signal received and a threshold voltage；When the ramp voltage is believed When number rising to the threshold voltage, the clock signal becomes effective status；
The output signal of the comparison circuit is as the clock signal.
13. the control circuit of buck-boost type converter according to claim 12, which is characterized in that the ramp signal hair Raw circuit includes the controllable current source and capacitance that are connected in series between voltage source and ground potential, is connected in parallel with the capacitance Controllable switch；
The on off state of the controllable switch is controlled by the clock signal；
The voltage signal of the public connecting end of the controllable current source and the capacitance is as the ramp voltage signal；
The output current of the controllable current source and the average value direct proportionality of the inductive current.
14. the control circuit of buck-boost type converter according to claim 9, which is characterized in that further include FREQUENCY CONTROL Circuit, to adjust the frequency of the clock signal according to the difference between the output voltage and desired output voltage.
15. the control circuit of buck-boost type converter according to claim 10, which is characterized in that further include FREQUENCY CONTROL Circuit, to adjust the clock signal according to the difference between first thermal compensation signal and second reference signal Frequency.
16. the control circuit of buck-boost type converter according to claim 15, which is characterized in that the FREQUENCY CONTROL electricity Road includes current regulating circuit, ramp generator and a comparison circuit；
In each switch periods, in the ineffective time section of the clock signal, what the ramp generator generated Ramp voltage signal linear rise；
The current regulating circuit is adjusting the rate of rise of the ramp voltage signal；
The comparison circuit is comparing the ramp voltage signal received and a threshold voltage；When the ramp voltage is believed When number rising to the threshold voltage, the clock signal becomes effective status；
The output signal of the comparison circuit is as the clock signal.
17. the control circuit of buck-boost type converter according to claim 16, which is characterized in that the ramp signal hair Raw circuit includes the current source and capacitance that are connected in series between voltage source and ground potential, is connected in parallel with the capacitance controllable Switch；
The on off state of the controllable switch is controlled by the clock signal；
Voltage signal on the public connecting end of the current source and the capacitance is as the ramp voltage signal；
The current regulating circuit is adjusting the charging current of the capacitance.
18. the control circuit of buck-boost type converter according to claim 17, which is characterized in that the current regulation electricity Road adjusts the charging current of the capacitance according to the error amount between first thermal compensation signal and second reference signal.
19. the control circuit of buck-boost type converter according to claim 18, which is characterized in that the current regulation electricity Road includes operational transconductance amplifier and single-way switch；
Two input terminals of the operational transconductance amplifier are received respectively according to first thermal compensation signal and second benchmark Signal；
The single-way switch be connected to the operational transconductance amplifier output terminal and the current source and the capacitance it is public Between connecting pin, the operational transconductance amplification is flowed to only to allow the public connecting end of electric current from the current source and the capacitance The output terminal of device.
20. the control circuit of buck-boost type converter according to claim 9, which is characterized in that the sampled signal hair Raw circuit includes,
Current sampling circuit to sample the inductive current, and generates current sampling signal according to this；
Holding circuit to receive the current sampling signal, and keeps the maximum of the current sampling signal, institute The output signal of holding circuit is stated as the sampled signal；
Sampling control circuit is connected between the current sampling circuit and the holding circuit, to control in each switch In cycle, the holding circuit receives the current sampling signal in the rise time section of the inductive current, described Inductive current rises to inductive current peak moment to current switch period finish time, and the sampled signal is maintained the electricity Flow the maximum of sampled signal.
21. a kind of buck-boost type converter, including power stage circuit, the conversion of claim 9-20 any one of them buck-boost type The control circuit and driving circuit of device；
The power stage circuit includes the first switch pipe and the 3rd switching tube that are connected in series between input voltage and ground potential； The second switch pipe and the 4th switching tube being connected in series between output voltage and ground potential；First end is connected to first switch pipe With the public connecting end of the 3rd switching tube, second end is connected to the electricity of the public connecting end of second switch pipe and the 4th switching tube Sense；And it is connected to the output capacitance of output terminal；
The driving circuit generates corresponding drive signal according to first control signal and second control signal.
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Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3560086B1 (en) * 2016-12-22 2021-09-15 Signify Holding B.V. Synchronous converter
WO2018223348A1 (en) 2017-06-08 2018-12-13 Texas Instruments Incorporated Non-inverting buck-boost converter control
CN108023468A (en) * 2017-12-28 2018-05-11 杰华特微电子（杭州）有限公司 Switching power source control circuit and Switching Power Supply
US10566902B1 (en) * 2018-08-22 2020-02-18 Semiconductor Components Industries, Llc Methods and systems of operating buck-boost converters
CN109617413B (en) * 2019-01-30 2024-03-01 上海艾为电子技术股份有限公司 Boost chip and mode switching circuit thereof
CN110350773B (en) * 2019-06-28 2020-11-20 长安大学 Current sampling and limiting circuit of four-switch Buck-Boost converter
CN110391804B (en) * 2019-07-23 2023-03-14 深圳市海派特光伏科技有限公司 Automatic frequency modulation method, device and equipment for electronic cigarette and storage medium
CN110536509B (en) * 2019-08-09 2022-01-07 矽力杰半导体技术(杭州)有限公司 Dimming control method and dimming control circuit and power converter applying same
CN111416519B (en) * 2020-05-07 2021-06-22 矽力杰半导体技术(杭州)有限公司 Inductive current reconstruction circuit, reconstruction method and power converter applying inductive current reconstruction circuit and reconstruction method
US11489445B2 (en) * 2020-10-08 2022-11-01 Analog Devices, Inc. Dynamic bias technique for enhanced MOSFET on-resistance based current sensing
CN112564482B (en) * 2020-12-08 2022-05-20 西安特来电智能充电科技有限公司 Four-switch-tube buck-boost converter control method and device, controller and storage medium
CN113162368B (en) * 2021-03-11 2023-02-10 成都芯源系统有限公司 DCR current sampling circuit and method and related control circuit
CN115473436B (en) * 2022-10-31 2023-03-14 杰华特微电子股份有限公司 Control circuit and control method of buck-boost converter
CN115882728B (en) * 2023-02-17 2023-05-16 杭州顺元微电子有限公司 Low-power-consumption buck conversion circuit for improving load adjustment rate
CN116667638B (en) * 2023-05-30 2024-05-07 南京理工大学 Linear-nonlinear peak current control strategy based on ZVS four-switch Buck-Boost circuit

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8319483B2 (en) * 2007-08-06 2012-11-27 Solaredge Technologies Ltd. Digital average input current control in power converter
CN102195481A (en) * 2010-03-19 2011-09-21 英特赛尔美国股份有限公司 Modulating scheme for using single comparator in constant-frequency step-up/step-down converter
CN102957312B (en) * 2011-08-19 2015-02-11 立锜科技股份有限公司 Power supply with over-current protection and control circuit and protection method thereof
CN105356746B (en) * 2015-12-04 2018-08-17 矽力杰半导体技术(杭州)有限公司 Turn-on time generation circuit and supply convertor for supply convertor

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