KR101304777B1 - DC/DC converter with wide input voltage range - Google Patents

Abstract

We present a DC-DC converter with a wide input voltage control range. The DC-DC converter according to the present invention is configured such that the input of the LLC resonant converter which is the main converter and the input of the auxiliary converter are connected in parallel, while the output of the LLC resonant converter and the output of the auxiliary converter are connected in series. Therefore, the magnetizing inductance of the resonant transformer may have a large value so that the LLC resonant converter may perform zero voltage switching, and thus the efficiency may be improved by operating at a fixed switching frequency near the resonance frequency in a certain input voltage range. In addition, when the input voltage is low, the sum of the output voltage generated by the auxiliary converter and the output voltage generated by the LLC resonant converter becomes the final output voltage, thereby generating a stable output voltage over a wide input voltage range.

Description

DC-DC converter with wide input voltage range

The present invention relates to a direct current-dc converter, and more particularly to a direct current-dc converter having a wide input voltage control range.

Devices such as photovoltaic module generators, fuel cell generators, and storage batteries output direct current voltages, but the voltage fluctuations that are typically output are large. Therefore, a DC-DC converter (hereinafter, referred to as a DC-DC converter) has been used to stably obtain a constant level of output.

DC-DC converters currently used to convert large fluctuations of output voltages into constant voltages, such as those described above, include boost converters and LLC resonant converters, or interleaved boosts. There is a two-stage DC-DC converter that combines an interleaved boost converter and an LLC resonant converter.

1 shows a two-stage DC-DC converter in which a boost converter and an LLC resonant converter are combined, and FIG. 2 shows a two-stage DC-DC converter in which an interleaved boost converter and an LLC resonant converter are combined. The operation waveform of the DC-DC converter of FIG. 2 is shown.

An operation waveform of the DC-DC converter of FIG. 2 will be described with reference to the operation waveform of FIG.

Switching signals S _G1 and S _{G2 each} having a duty ratio of a predetermined (discontinuous mode DCM in FIG. 3) and having a phase difference of 180 degrees are applied to the gates of the switch elements S ₁ and S ₂ of the interleaved boost converter. . In the interleaved boost converter, two boost converters are alternately arranged, and two switching signals S _G1 and S _G2 activate one boost converter.

When the first switching converter is a switching element (S ₁₎ is turned on by a switching signal (S _G1), an inductor (L _B1) to flow a current (I _LB1) is the energy is accumulated in the inductor (L _B1). In this case, the voltage difference V _S1 across the switch element S _G1 , that is, the voltage difference between the node N _B1 and the node N _G1 is 0V since the switch element S ₁ is turned on. However, when the voltage level of the switching signal S _G1 is lowered and the switch element S ₁ is turned off, the reverse voltage V _LB1 due to the reset current from the inductor L _B1 is added to the input voltage V _in to boost the voltage. The boosted voltage V _in + V _LB1 is applied to the LLC resonant converter as the combined voltage V _link . Since the reverse voltage V _LB1 is not a sustained voltage, the voltage V _S1 between the both ends of the switch element S _G1 represents a ripple after a predetermined time.

Meanwhile, the first switching converter performs an operation in response to the switching signal S _G2 , and the process of the operation is the same as that of the first switching converter. However, since the switching signals S _G1 and S _G2 alternately operate with a phase difference of 180 degrees, the interleaved boost converter transmits the coupled voltage V _link which is stably boosted more than the single boost converter to the LLC resonant converter.

Switching signals S _G3 and S _G4 are applied to the gates of the main switch elements S ₃ and S ₄ of the LLC resonant converter with a fixed duty ratio (50% in FIG. 3), and switching signals S _G3 and S 4. In response to _G4 ), the main switch elements S ₃ , S ₄ are alternately turned on / off. Accordingly, voltages V _ab and V _cd are alternately applied to the first winding end of the transformer T _r of the LLC resonant converter, and are shown in FIG. 3 by resonant with the capacitors C _r1 and C _r2 . As described above, the AC current I _T1 flows, and the current I _m flows through the magnetizing inductance L _m . Where L _l is the leakage inductance. On the other hand, the second winding end of the transformer (T _r ) of the LLC resonant converter has four diodes (D _L1 to D _L4 ) and the alternating current voltage induced in response to the resonant current (I _T1 ) applied to the first winding end. Full-wave rectification using a capacitor (C _out ) to apply the output voltage (V _out ) to the load (R _LD ).

That is, in the DC-DC converter of FIG. 2, the boost converter or the interleaved boost converter performs an operation of boosting the power supply voltage V _in applied to a device such as a solar module generator, a fuel cell generator, and a storage battery to a constant voltage. The LLC resonant converter operates at a fixed duty ratio to output a stable output voltage (V _out ).

The DC-DC converter of FIG. 1 is composed of a single boost converter and an LLC resonant converter rather than an interleaved boost converter and an LLC resonant converter, and is similar to the operation of the DC-DC converter of FIG.

In general, the LLC resonant converter outputs the magnetizing inductance (L _m ) of the transformer (T _r ) of the LLC resonant converter in order to output a wide range of input voltage (V _in ) to a constant output voltage (V _out ). Design small. However, if the magnetizing inductance L _m is designed small, the conduction loss is increased due to the large magnetizing current.

In the DC-DC converter of FIGS. 1 and 2 composed of two-stage converters, in order to solve the above-described problems of the LLC resonant converter, the main switch elements S ₃ and S ₄ of the LLC resonant converter have zero voltage switching. Switching: Applying large magnetization inductance (L _m ) to perform ZVS, and switching signal (S _G3 , S _G4) to operate at constant switching frequency in the resonant frequency range when input voltage (V _in ) is in a certain range. ) To achieve high efficiency. However, when the input voltage V _in decreases, the boost converter or the interleaved boost converter operates by activating the switch elements S ₁ and S ₂ by using the switching signals S _G1 and S _G2 , whereby the combined voltage V _link Increase the voltage level of) to maintain constant output voltage (V _out ) at all times.

)은 승압 컨버터의 효율(

)과 LLC 공진 컨버터(

)의 곱(

)으로 계산되므로, 승압 컨버터의 낮은 효율은 전체 DC-DC 컨버터의 효율을 저감시키는 원인이 된다. 또한 모든 입력전압(V_in) 및 부하 조건에서 승압 컨버터는 정격 부하로서 설계되고 동작하기 때문에 DC-DC 컨버터 전체의 제조비용을 상승시키게 되는 문제를 갖고 있다.
However, although the LLC resonant converter can obtain high efficiency through zero voltage switching in a constant input voltage range, the boost converter does not have high efficiency because it performs hard switching as shown in FIG. 3. And overall efficiency (

Is the efficiency of the boost converter

) And LLC resonant converter

) Times (

Low efficiency of the boost converter causes the efficiency of the entire DC-DC converter to be reduced. In addition, the boost converter is designed and operated as a rated load at all input voltages (V _in ) and load conditions, thereby increasing the manufacturing cost of the entire DC-DC converter.

An object of the present invention is to provide a DC-DC converter having a wide input voltage control range with high efficiency.

One example of a DC-DC converter for achieving the above object is connected to a resonant input unit for inducing a current change in a first winding end of a resonant transformer by receiving an input voltage, and connected to the second winding end of the resonant transformer. A main converter having a resonant output unit configured to generate a voltage corresponding to a change in current of the first winding stage, and then rectify and generate an output voltage, and an auxiliary input unit connected in parallel with the resonant input unit with respect to the input voltage; An auxiliary output unit connected in series with the resonant output unit with respect to the output voltage, and activated when the voltage level of the input voltage is lower than a specified reference voltage to increase the voltage level of the output voltage generated in the main converter; And an auxiliary converter, wherein the auxiliary converter is configured such that when the input voltage is lower than the reference voltage, It is activated in response to the voltage level of the ryeokjeonap characterized in that to raise the voltage level of the output voltage.

delete

The resonance input unit for achieving the object is a switching unit having a first and second switch element connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input voltage A resonator including first and second resonant capacitors connected in series with the switching unit and connected in series between the input node and the first ground node, and a first interposed between the first and second switch elements. And the first winding end of the resonant transformer connected between a first conversion node and a second conversion node between the first and second resonant capacitors.

In order to achieve the above object, the first and second switch elements are activated in response to the first and second switching signals applied at fixed ratios, respectively, to perform zero voltage switching.

A resonance input unit for achieving the above object includes a first and second switch elements connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input node. A second switching unit having a third and fourth switch elements connected in parallel with the switching unit and connected in series between the input node and the first ground node, and the first and second switches And a first winding end of the resonant transformer and a resonant capacitor connected in series between a first conversion node between the elements and a second conversion node between the third and fourth switch elements.

The resonance output unit for achieving the above object comprises a first second winding end of the resonant transformer connected in series between a first output node to which the output voltage is output and a second output node to which one end of the auxiliary converter is connected; A first resonant output having a first output diode, a second second winding end of said resonant transformer connected in series between said first and second output nodes in parallel with said first resonant output; And a second resonant output having a second output diode, and an output capacitor connected in parallel with the first and second resonant outputs between the first output node and the second output node.

The auxiliary converter for achieving the above object is characterized in that one of the interleaved flyback converter, single flyback converter, push-pull converter and forward converter.

The auxiliary input unit for achieving the above object comprises a first flyback input unit having a first winding end and a first flyback switch element of a first flyback transformer connected in series between the input node and the first ground node; And a first winding end of the second flyback transformer and a second flyback switch element connected in parallel with the first flyback input unit and connected in series between the input node and the first ground node. And a flyback input unit.

The auxiliary output unit for achieving the above object comprises a first flyback output having a third output diode connected in series between the second output node and the second ground node and a second winding end of the first flyback transformer; A second flyback output having a second winding end of a fourth output diode and a second flyback transformer connected in series between the second output node and the second ground node, and the second output node and the And a flyback output capacitor having a flyback output capacitor and a fifth output diode connected between the second ground nodes.

Another example of a DC-DC converter for achieving the above object is a main resonance input unit which receives an input voltage and induces a current change in a first winding end of a resonant transformer, and a voltage level of the input voltage is lower than a predetermined reference voltage. An input terminal having an interleaved half-wave current resonant input configured to alternately induce a current change in a first winding end of each of the first and second half-wave resonant transformers, and connected to a second winding end of the resonant transformer to resonate A resonant output part which generates a voltage corresponding to the voltage change of the first winding end of the transformer and then rectifies and generates an output voltage and is connected to the second winding end of the first and second half-wave current resonant transformers And an output stage including a half-wave current resonant output unit for raising a voltage level of the output voltage generated in the second stage.

The resonance input unit for achieving the above object is a switching unit having a first and second switch element connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input node A resonator including first and second resonant capacitors connected in series with the switching unit and connected in series between the input node and the first ground node, and a first interposed between the first and second switch elements. And the first winding end of the resonant transformer connected between a first conversion node and a second conversion node between the first and second resonant capacitors.

To achieve the above object, an interleaved half-wave current resonant input unit includes a first half-wave current resonant switch element and a first half-wave current resonant diode connected in series between the input node and the first ground node, and the first half-wave current resonant switch. And a first winding end and a first half-wave current resonant capacitor of the first half-wave current resonant transformer connected in series between a third conversion node between the device and the first half-wave current resonant diode and the first conversion node. A first half wave current resonant input unit and a second half wave current resonant diode and a second half wave current resonant switch element connected in series between the input node and the first ground node, the second half wave current resonant diode and the second half wave The second half-wave hole connected in series between a fourth conversion node between the current resonant switch element and the first conversion node. And a second half-wave current resonant input having the first winding end of the true transformer and a second half-wave current resonant capacitor.

The interleaved half-wave current resonant input unit for achieving the above object is the first winding end and the first half-wave current resonant capacitor of the first half-wave current resonant transformer connected in series between the first conversion node and the first ground node, And a first half-wave current resonant switch element, and a first half-wave current resonant diode connected between the first and third conversion nodes between the first half-wave current resonant capacitor and the first half-wave current resonant switch element. A first half wave current resonant input unit, and a first half end of the second half wave current resonant transformer and a second half wave current resonant capacitor and a second half wave current resonant switch connected in series between the input node and the first conversion node. A fourth conversion between the second half-wave current resonant capacitor and the second half-wave current resonant switch element The claim, characterized in that it comprises two half-wave current resonance type section having a DE and the second half-wave resonance current diode connected between the input node.

A first winding of the resonant transformer is connected in series between a first output node to which the output voltage is output and a second output node to which one end of the half-wave current resonant output part is connected. A first resonant output having a first output diode and a second second winding of the resonant transformer connected in series between the first and second output nodes in parallel with the first resonant output; And a second resonant output having a second output diode and an output capacitor connected in parallel with the first and second resonant outputs between the first output node and the second output node. do.

A half wave current resonant output unit for achieving the above object includes a first half wave having a third output diode connected in series between the second output node and a second ground node and a second winding end of the first half wave current resonant transformer. A second half-wave current resonant output having a current resonant output, a fourth output diode connected in series between the second output node and the second ground node, and a second winding end of the second half-wave current resonant transformer; And a half-wave current resonant output capacitor unit including a half-wave current resonant output capacitor and a fifth output diode connected between the second output node and the second ground node.

Therefore, when the voltage level of the input voltage is high, the DC-DC converter of the present invention can output a constant output voltage by the LLC resonant converter, and when the voltage level of the input voltage is lowered, the interleaved flyback converter is alternately operated. The output voltage of the LLC resonant converter can be supplemented to obtain a stable and stable output voltage efficiently. In addition, since the LLC resonant converter can handle the full load at the minimum 1/2 load depending on the voltage level of the input voltage, the interleaved flyback converter only needs to bear the load less than 1/2 the maximum rated load. It can reduce stress and reduce manufacturing cost.

1 shows a DC-DC converter in a two stage configuration in which a conventional boost converter and an LLC resonant converter are combined.
2 shows a DC-DC converter in a two stage configuration in which a conventional interleaved boost converter and an LLC resonant converter are combined.
3 shows an operating waveform of the DC-DC converter of FIG.
4 shows an example of a DC-DC converter according to the present invention.
5 shows an operating waveform of the DC-DC converter of FIG.
FIG. 6 shows another variation of the DC-DC converter of FIG. 4.
7 and 8 show another example of the resonance output unit.
9 shows another example of a DC-DC converter according to the present invention.
10 and 11 show another example of the DC-DC converter according to the present invention.
12 shows operational waveforms of the DC-DC converter of FIGS. 10 and 11.
13 and 14 show another example of the DC-DC converter according to the present invention.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention can be implemented in various different forms, and is not limited to the embodiments described. In order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals in the drawings denote the same members.

Throughout the specification, when an element is referred to as " including " an element, it does not exclude other elements unless specifically stated to the contrary. The terms "part", "unit", "module", "block", and the like described in the specification mean units for processing at least one function or operation, And a combination of software.

4 shows an example of a DC-DC converter according to the present invention.

The DC-DC converter according to the embodiment of the present invention shown in FIG. 4 has a structure in which an interleaved flyback converter and an LLC resonant converter are combined. The configuration of the DC-DC converter of FIG. 4 can be largely divided into an input terminal 110 and an output terminal 120. First, the input terminal 110 includes a flyback input unit and a resonance input unit connected in parallel with the input voltage V _in , respectively, between the input node N _in and the first ground node N _G1 . Since the DC-DC converter uses an interleaved flyback converter, the flyback input unit includes a first flyback input unit and a second flyback input unit connected in parallel between the input node N _in and the first ground node N _G1 . Equipped. The first and second flyback inputs are first windings of the first and second flyback transformers T ₂ and T ₃ connected in series between the input node N _in and the first ground node N _G1, respectively. And first and second flyback switch elements Q ₃ and Q ₄ .

The resonant input unit may include a switching unit connected in parallel between the input node N _in and the first ground node N _G1 , and a first resonant transformer T ₁ connected between the resonating unit and the switching unit and the resonating unit, respectively. A winding end is provided. The first and second main switch elements Q ₁ and Q ₂ and the first and second resonant capacitors are connected in series between the input node N _in and the first ground node N _G1, respectively. (C _r1 , C _r2 ). The first winding end of the resonant transformer T ₁ may include a first conversion node N _T1 between the first and second main switch elements Q ₁ and Q ₂ , and first and second resonant capacitors C _r1,. C _r2 ) between the second transform node N _T2 .

The output terminal 120 includes a resonance output unit and a flyback output unit. The resonant output unit the output voltage (V _o1) a first output node which outputs (N _o1) and the second output node (N _o2) in comprising a first and a sub second resonant output and the resonant output capacitor connected in parallel between the . The first resonant output unit has a first second winding end and a first output diode D ₅ of the resonant transformer T ₁ connected in series between the first output node _NO 1 and the second output node N _o2 . And a second resonant output part having a second second winding end and a second output diode D ₆ of the resonant transformer T ₁ connected in series, and the resonant output capacitor part resonant output capacitor C ₁ . It is provided.

The output unit may be a flyback second output node (N _o2) and a second ground node (N _G2) for comprising a first and a second flyback output and a flyback capacitor connected in parallel between the output. The first flyback output has a second winding end of the first flyback transformer T ₂ and a third output diode D ₇ connected in series, and the second flyback output is connected in series. The second winding end of the transformer T ₃ and the fourth output diode D ₈ are provided, and the flyback output unit has a second output node _{NO o2} and a second ground node N at which the output voltage V _o2 is output. A flyback output capacitor C ₂ and a fifth output diode D ₉ are connected between _G2 ).

The output voltage V _o = V _{01 +} V ₀₂ is applied to the load R _LD as a voltage difference between the first output node N _o1 and the second ground node N _G2 .

5 shows an operating waveform of the DC-DC converter of FIG.

Hereinafter, the operation of the DC-DC converter of FIG. 4 will be described with reference to FIG. 5. Referring to the operation of the LLC resonant converter, the duty ratio of the first and second resonant switching signals V _G1 and V _G2 is fixed to the gates of the main switch elements Q ₁ and Q ₂ of the LLC resonant converter. 50%), and the main switch elements Q ₁ and Q ₂ are alternately turned on / off in response to the first and second resonance switching signals V _G1 and V _G1 . As shown in FIG. 5, the voltages V _ab and V _cd applied to both ends of each of the two main switch elements Q ₁ and Q ₂ alternately transition to a voltage level equal to the input voltage V _in . . And a voltage (V _ab, V _cd) is a resonant transformer (T ₁₎ and the resonant capacitor is applied to the (C _r1, C _r2) resonant transformer (T ₁₎ the first winding stage, the alternating current as shown in Figure 5 of The resonant current I _T1 flows, and the current I _m1 flows through the magnetizing inductance L _m1 . L _l11 in Fig. 4 represents the leakage inductance.

It is assumed that there is no voltage difference V _ab across the first main switch element Q ₁ during the period in which the first main switch element Q ₁ is turned on and the second main switch element Q ₂ is turned off. As a result, it can be seen that the input voltage V _in is the voltage difference V _cd between both ends of the second main switch element Q ₂ . The charging current flows to the second resonant capacitor C _r2 opposite to the resonant current I _T1 . At the same time, a discharge current flows from the first resonant capacitor C _r1 through the first main switch element Q ₁ and the resonant transformer T ₁ . That is, as shown in FIG. 5, a negative resonant current I _T1 is applied to the resonant transformer T ₁ .

On the other hand from the second winding wire terminal of one of the sub-resonance output of the output stage 120, a current resonance transformer (T ₁₎ which is induced by the resonant transformer (T ₁₎ the first winding stage resonant current (I _T1) flows in the the second output diode (D ₆₎ it is applied in a direction, but the second output diode, the current does not flow, so that the reverse bias is applied to the (D _6). On the other hand, the current induced in the first second winding end of the resonant transformer T ₁ is forward biased to the second output diode D ₅ so that the resonant output part outputs the output voltage through the first output node N _o1 . (V _o1 ) is output.

On the other hand, during the period in which the first main switch element Q ₁ is turned off and the second main switch element Q ₂ is turned on, there is no voltage difference V _cd between both ends of the second main switch element Q ₂ . It can be considered that the input voltage V _in is the voltage difference V _ab between the both ends of the first main switch element Q ₁ . Therefore, the charging current flows from the first resonant capacitor C _r1 toward the second main switch element Q ₂ through the resonant transformer T ₁ . At the same time, a discharge current flows from the second resonant capacitor C _r2 through the resonant transformer T ₁ and the second main switch element Q ₂ .

The resonant transformer (T ₁₎ of claim 1, the second output diode (D ₆₎ direction from the second secondary winding terminal of the current resonant transformer (T ₁₎ which is induced by the resonant current (I _T1) flowing through the winding end of the Since a forward bias is applied to the second output diode D ₆ , the output voltage V _o1 is output through the first output node N _o1 . However, in the current induced in the second winding end of the resonant transformer T ₁ , a reverse bias is applied to the first output diode D ₅ so that no current flows.

The output capacitor C ₁ smoothes the output voltage V _o1 .

On the other hand, when the interleaved flyback converter is operated, the gates of the first and second flyback switch elements Q ₃ and Q ₄ have a ratio of a predetermined ratio (discontinuous mode DC in FIG. 5) and a phase difference of 180 degrees. The first and second flyback switching signals V _G3 and V _G4 having are applied.

When the switch element Q ₃ is turned on by the first flyback switching signal V _G3 at the first flyback input unit, a current I _T2 is applied to the first winding end of the first flyback transformer T ₂ . As it flows, energy is accumulated in the magnetization inductance L _m2 . In this case, the voltage difference V _Q3 across the switch element Q ₃ may be considered to be ideally absent. However, when the voltage level of the first flyback switching signal V _G3 is lowered and the switch element Q ₃ is turned off, the energy accumulated in the magnetization inductance L _m2 is the second of the first flyback transformer T ₂ . The energy accumulated in the winding ends is reset and transferred to the output. At this time, during the reset period, the voltage ((n _{T2 -1} / n _{T2 -2} ) V _o2 ) and the input voltage V induced from the second winding end of the first flyback transformer T ₂ to the first winding end. the sum voltage _{(V in + (n T2 -1} / n T2 -2) V o2) of the _in) is applied to the switch device (Q ₃₎ at both ends (V _Q3). Here, _T2 n _-1 has a first flyback transformer first winding end turns of the (T ₂₎ - the number, n _{T2 -2} has a first flyback second winding end turns of the transformer (T ₂₎ - the number. After the energy accumulated in the magnetization inductance L _m2 is reset, the voltages of the first winding end and the second winding end of the first flyback transformer T ₂ become 0, and the voltage between the both ends of the switch element Q ₃ is reduced. (V _Q3 ) is represented by the input voltage (V _in ).

On the other hand, while the switch element Q ₃ is turned on and voltage is induced in response to the current I _T2 flowing in the first winding end of the first flyback transformer T ₂ , the first flyback of the first flyback output unit The voltage in the reverse bias direction is induced in the third output diode D ₇ at the second winding end of the transformer T ₂ by the winding direction of the winding. Since the voltage is induced in the reverse bias direction to the third output diode D ₇ , no current flows, and energy is accumulated only in the magnetizing inductance L _{m 2} of the first winding end. Then, when the switch element Q ₃ is turned off, a voltage having a polarity opposite to that of the previous state is induced at the second winding end of the first flyback transformer T ₂ , and a forward bias direction is applied to the third output diode D ₇ . The voltage is induced to apply a voltage V _o2 of a predetermined level between the second output node N _o2 and the second ground node N _G2 .

The operation of the second flyback input unit and the second flyback output unit is similar to the first flyback input unit and the first flyback output unit. However, since the second flyback switching signal V _G4 applied to the switch element Q ₄ has a 180-degree phase difference from the first flyback switching signal V _G3 , as a result, the first and second flyback output units Alternately, a predetermined voltage V _o2 is applied to the second output node N _o2 , and the flyback output capacitor C ₂ stabilizes the voltage level of the second output node N _o2 . That is, the voltage level of the second output node _NO2 is kept constant.

In FIG. 5, the first and second flyback switching signals V _G3 and V _G4 have a fixed duty ratio and switching frequency, but the first and second flyback switching signals V _G3 and V _G4 The duty ratio and switching frequency may be adjusted corresponding to the voltage level of the input voltage V _in . When the input voltage V _in is applied at a predetermined maximum level, the interleaved flyback converter may be deactivated by applying the first and second flyback switching signals V _G3 and V _G4 to a low level. This is because when the input voltage V _in is applied at a sufficiently high voltage level, only the LLC resonant converter can output the stable output voltage V _o . In other words, in the interleaved flyback converter, when the voltage level of the input voltage V _in decreases, the interleaved flyback converter increases the voltage level of the second output node N _o2 by the lowered voltage level, resulting in an output voltage. (V _o) is V (the second output node, the sum of the first output node voltage (V _o1) of the (N _o1) generated by the voltage (V _o2) and LLC resonant converters (N _{o2) o} = V _o1 + V _o2 ) to maintain a stable voltage level. Therefore, even if the variation range of the input voltage (V _in ) is large, the output voltage (V _o ) can be maintained.

The conventional DC-DC converter shown in FIG. 2 has a series connection structure in which an interleaved boost converter boosts an input voltage V _in of a low voltage level and applies a combined voltage V _link to an LLC resonant converter. Also interleaving step-up converter does not directly control the output voltage (V _o), the number was only through the LLC resonant converter to control the output voltage (V _o). However, in the DC-DC converter shown in FIG. 4, the interleaved flyback converter and the LLC resonant converter are coupled in parallel at the input unit, and the interleaved flyback converter and the LLC resonant converter are coupled in the series at the output unit. In other words, the interleaved flyback converter also enables direct adjustment of the output voltage (V _o ) in response to the input voltage (V _in ).

In addition, the interleaved flyback converter only bears a maximum voltage of 1/2 of the output voltage (V _o ), so it only needs to deliver about half the power capacity of the full DC-DC converter maximum rated load. Thus, device ratings and current stress can be reduced. As a result, manufacturing costs can be reduced compared to conventional two-stage DC-DC converters, enabling high efficiency over a wide input voltage range.

In FIG. 5, the first and second flyback switching signals V _G3 and V _{G4 are} shown to be synchronized with the first and second resonant switching signals V _G1 and V _G2 . The signals V _G3 and V _G4 may be controlled asynchronously with the first and second resonant switching signals V _G1 and V _G2 , and the interleaved flyback converter may be in a discontinuous conduction mode (DCM), It can be controlled by various methods such as Continuous Conduction Mode (CCM) and Quasi-Resonant Converter (QRC).

FIG. 6 is another variation of the DC-DC converter of FIG. 4, wherein the configuration of the output stage is partially different from that of FIG. When the resonant output part of the DC-DC converter of FIG. 6 is compared with the DC-DC converter of FIG. 4, the mutual positions of the second winding end and the output diode of the resonant transformer constituting the first resonant output part and the second resonant output part are changed. . That is, a first output diode D ₅ and a first second winding end of the resonant transformer T ₁ connected in series between the first output node _NO 1 and the second output node _NO 2 are provided. The second resonant output part includes a second output diode D ₆ connected in series and a second second winding end of the resonant transformer T ₁ .

Similarly, the flyback output of the DC-DC converter of FIG. 6 includes a third winding diode D ₇ and a second winding end of the first flyback transformer T ₂ connected in series. The second flyback output unit has a second winding end of the fourth output diode D ₈ and the second flyback transformer T ₃ connected in series.

That is, the positions of the first and second winding ends and the first to fourth output diodes D ₅ to D ₈ of the transformers T ₁ and T ₂ having the configuration connected in series are interchangeable.

The rest of the configuration of the DC-DC converter of FIG. 6 is the same as that of the DC-DC converter of FIG.

7 and 8 show another example of the resonance output unit.

The resonant output unit in the DC-DC converter of FIGS. 4 and 6 may be implemented using a single bridge rectifier and a double rectifier shown in FIGS. 7 and 8.

Even when the resonant output unit is implemented as the single bridge rectifier of FIG. 7 and the doubler rectifier of FIG. 8, the flyback output unit and the second output node _NO2 are connected like the resonant output unit of FIGS. 4 and 6.

9 shows another example of a DC-DC converter according to the present invention.

The DC-DC converter of FIG. 9 is a DC-DC converter in which an interleaved flyback converter and an LLC resonant converter are combined like the DC-DC converter of FIG. 4. However, the LLC resonant converter of the DC-DC converter of FIG. 9 is a full bridge LLC resonant converter, and the configuration of the resonant input unit is different from that of the DC-DC converter of FIG. In FIG. 9, the full bridge LLC resonant converter is a third and fourth switch element S ₃ connected in series between the input node N _in and the first ground node N _G1 instead of the resonator of the LLC resonant converter of FIG. 4. ₄ , except that one capacitor is connected in series to the first winding end of the resonant transformer T ₁ as the resonant capacitor C _r1 . It has the same configuration as the converter. The third and fourth switch elements S ₃ and S _{4 of} the second switching unit have a ratio corresponding to the switching signals V _G1 and V _G2 applied to the first and second switch elements S ₁ and S ₂ . Receives a switching signal (not shown) having the on / off to supply current to the first winding end and the resonant capacitor (C _r1 ) of the resonant transformer (T ₁ ).

Since the operation of the DC-DC converter of FIG. 9 is similar to that of the DC-DC converter of FIG. 4, a detailed description thereof will be omitted.

4, 6 and 9 illustrate a DC-DC converter in which an interleaved flyback converter and an LLC resonant converter are combined, but a single flyback converter and a push-pull converter that are not interleaved flyback converters. It is also possible to combine LLC resonant converters with converters such as a Pull Converter and a Forward Converter.

As a result, the DC-DC converter according to the present invention allows the magnetization inductance L _m of the resonant transformer to have a large value so that the main switch elements Q ₁ and Q ₂ of the LLC resonant converter can perform zero voltage switching. In the constant input voltage (V _in ) range to operate at a fixed switching frequency near the resonant frequency to improve the efficiency, and to operate at a fixed rate of application without variation in duty and switching frequency. In addition, when no load condition and the voltage rises too high, the switching frequency control operation and the burst mode switching operation control which is intermittently switched within a certain gain range is possible as needed. The interleaved flyback converter is activated when the voltage level of the input voltage V _in is lowered, thereby assisting the output voltage V _o to be constant.

Therefore, the DC-DC converter of FIGS. 4 and 6 outputs the output voltage V _o using the LLC resonant converter as the main converter, and when the voltage level of the input voltage V _in is low, an interleaved flyback converter, a single Auxiliary converters such as flyback converters, push-pull converters and forward converters complement the output voltage (V _o ) for efficient DC-DC conversion over a wide input voltage range Do this.

10 and 11 show another example of the DC-DC converter according to the present invention.

10 is an interleaved half-wave current resonant converter applied as a one-stage DC-DC converter in which three resonant converters are combined. In the configuration, the input and output stages are largely similar to the DC-DC converters of FIGS. 4, 6, and 7. It can be divided into

Referring to the configuration of the DC-DC converter of FIG. 10, first, an input terminal includes a main resonant input unit and an interleaved half-wave current connected in parallel with an input voltage V _in between an input node N _in and a first ground node N _G1 . It has a resonance input unit. The main resonance input unit has a switching unit and a resonance unit similar to the resonance input unit of FIG. 4, and the switching unit and the resonance unit are respectively connected in series between the input node N _in and the first ground node N _G1 . And first and second main switch elements Q ₁ , Q ₂ and first and second resonant capacitors C _r1 , C _r2 . The first winding end of the resonant transformer T ₁ may include a first conversion node N _T1 between the first and second main switch elements Q ₁ and Q ₂ , and first and second resonant capacitors C _r1,. C _r2 ) between the second transform node N _T2 .

Meanwhile, since the DC-DC converter of FIG. 10 uses an interleaved half-wave current resonant converter, an interleaved half-wave current resonant input unit is provided instead of an interleaved flyback input unit. The interleaved half-wave current resonant input unit includes a first half-wave current resonant input unit and a second half-wave current resonant input unit, and the first half-wave current resonant input unit is connected in series between the input node N _in and the first ground node N _G1 . And a first half wave diode D ₃ and a first half wave switch element Q ₃ . In addition, the first half-wave current resonant input unit is connected in series between the third conversion node (N _T3 ) and the first conversion node (N _T1 ) between the first half-wave diode (D ₃ ) and the first half-wave switch element (Q ₃ ). And a first winding end of the first half-wave current resonant transformer T ₂ and a first half-wave current resonant capacitor _Cr 3.

Similarly, the second half-wave current resonant input unit connects the second half-wave switch element Q ₄ and the second half-wave diode D ₄ connected in series between the input node N _in and the first ground node N _G1 . And a second half wave current connected in series between the fourth conversion node N _T4 and the first conversion node N _T1 between the second half wave switch element Q ₄ and the second half wave diode D ₄ . A resonant transformer T ₃ and a second half-wave current resonant capacitor _{Cr r 4} are provided.

The output stage includes a resonance output section and a half-wave current resonance output section. Like the resonant output part of FIG. 4, the resonant output part of FIG. 10 also includes a first and a second connected in parallel between the first output node N _o1 and the second output node N _{o2 from} which the output voltage V _o1 is output. And a resonant output section and an output capacitor section. The first resonant output unit has a first first winding end and a first output diode D ₅ of the resonant transformer T ₁ connected in series between the first output node _NO 1 and the second output node N _o2 . And a second resonant output part having a second second winding end and a second output diode D ₆ of the resonant transformer T ₁ connected in series, and the output capacitor part having an output capacitor C ₁ . do. Here, since the second winding end of the resonant transformer constituting the first resonant output unit and the second resonant output unit and the output diode are connected in series, mutual positions may be changed.

The half wave current resonant output part includes first and second half wave current resonant output parts and a half wave current resonant output capacitor part connected in parallel between the second output node _NO 2 and the second ground node N _G2 . The first half wave current resonant output part includes a second winding end of the first half wave current resonant transformer T ₂ and a third output diode D ₇ connected in series, and the second half wave current resonant output part is connected in series. The second half-wave current resonant transformer T ₃ has a second winding end and a fourth output diode D ₈ , and the half-wave current resonant output capacitor portion is between the second output node _NO 2 and the second ground node N _G2 . An output capacitor C ₂ and a fifth output diode D ₉ connected in parallel with each other. Since the second winding end of the first half-wave current resonant output unit and the second half-wave current resonant output unit, and the output diode are also connected in series, their positions may be changed.

That is, the configuration of the resonant output unit at the output terminal of FIG. 10 is the same as that of the resonant output unit of FIG. The second winding stage configuration of the half-wave current resonant transformers T ₂ , T ₃ is applied.

The output voltage _Vo is applied to the load R _LD as a voltage difference between the first output node N _o1 and the second ground node N _G2 , similarly to the DC-DC converter of FIG. 4.

The DC-DC converter of FIG. 11 is also a single stage DC-DC converter in which three resonant converters are combined similarly to the DC-DC converter of FIG.

The DC-DC converter of FIG. 11 may also be divided into an input stage and an output stage, and the input stage may be divided into a main resonance input unit and an interleaved half-wave current resonance input unit. The configuration of the main resonance input section at the input stage is the same as that of the main resonance input section in FIG. However, in FIG. 11, the first and second half wave resonant input parts of the interleaved half wave current resonant input part have a different structure from those of the first and second half wave current resonant input parts of FIG. 10. In FIG. 11, the first half-wave current resonant input unit has a first winding end and a first winding end of a first half-wave current resonant transformer T ₂ connected in series between the first conversion node N _T1 and the first ground node N _G1 . A half wave current resonant capacitor C _r3 and a first half wave switch element Q ₃ are provided. And a first resonant diode D connected between the first conversion node N _T1 , the first half wave current resonant capacitor C _r3 , and the third conversion node N _T3 between the first half wave switch element Q ₃ . ₃ ).

Similarly, the second half wave current resonant input unit has a first winding end and a second half wave current of the second half wave current resonant transformer T ₃ connected in series between the input node N _in and the first conversion node N _T1 . A resonant capacitor C _r4 and a second half wave switch element Q ₄ , and provided between the input node N _in and the second half wave current resonant capacitor C _r4 and the second half wave switch element Q ₄ . And a second resonant diode D ₄ connected between the four conversion nodes N _T4 .

12 shows operational waveforms of the DC-DC converter of FIGS. 10 and 11.

Operation of the main resonance input unit and the resonance output unit is basically the same as that of the LLC resonant converter of FIG.

Referring to the operation of the first half-wave current resonant input unit in the interleaved half-wave current resonant input unit, when the first main switch element Q ₁ of the LLC resonant converter is turned on, in response to the third half-wave resonant switching signal G ₃ . The first half wave switch element Q ₃ of the one half wave current resonant converter is turned on. Since the second main switch element Q ₂ of the LLC resonant converter is turned off, the resonant current (T ₁ ) is passed from the input node N _in to the winding side of the resonant transformer T ₁ through the first conversion node N _T1 . I _T1 ) flows through the first half-wave current resonant capacitor C _r3 and the first winding end of the first half-wave current resonant transformer T ₂ and through the turned-on first half-wave switch element Q ₃ . One half-wave resonant current I _T2 flows. At this time, when the first half-wave switch element Q ₃ is turned on, the first half-wave resonant current I _T2 increases rapidly due to the influence of the first half-wave current resonant capacitor C _r3 , and then gradually increases. The first half-wave a second winding end of the current resonant transformer (T ₂₎ the first winding only the first half-wave resonance current (I _T2) the first half-wave current resonance transformer (T ₂₎ while a voltage is induced by the in, the third The voltage in the reverse bias direction is induced in the output diode D ₇ . Therefore, no current flows, and energy is accumulated only in the magnetization inductance L _m2 of the first winding end. Then, when the first main switch element Q ₁ of the LLC resonant converter is turned off, since the input node N _in and the first conversion node N _T1 are not directly connected, the first half-wave resonant current I _T2 is but the slightly reduced, and is gradually reduced by the first winding end of the resonant transformer (T ₁₎ the first coil end and the first half-wave current resonance transformer (T ₂₎ of the. When the second main switch element Q ₂ is turned on, the first half wave resonant current I _T2 is converted to the first half wave current resonant transformer T ₂ by the discharge voltage of the first half wave current resonant capacitor _{Cr r3} . A negative current flows through the antiparallel diodes of the first winding end of the second winding, the second main switch element Q ₂ , and the first half wave switch element Q ₃ . Therefore, if the first half-wave switch element Q ₃ of the first half-wave current resonant converter is turned off with a delay as shown in FIG. 12, the switching loss can be reduced by turning off at a zero voltage condition. The first half-wave a second winding end, the forward bias to the third output diode (D ₇₎ of the current resonant transformer (T ₂₎ the first half-wave current resonance transformer (T ₂₎ in response to the voltage induced to the first winding end of the the direction of the voltage is organic the second output node voltage of a predetermined level between the (N _o2) and a second ground node (N _G2) is applied.

The second half-wave current resonant input unit also operates similarly to the first half-wave current resonant input unit, but since the first and second half-wave resonant switching signals G ₁ and G ₂ have a phase difference of 180 degrees with each other, the first half-wave current resonance The predetermined voltage V _o2 is applied to the second output node N _o2 alternately with the input unit.

Although the operation of the main resonant input unit and the resonant output unit is the same as that of the LLC resonant converter of FIG. 5, the interleaved half-wave current resonant converter of the DC-DC converter of FIG. 10 is directly connected to the first conversion node N _T1 . And since the current is applied, the waveform of the resonant current (I _T1 ) flowing through the first winding end of the resonant transformer (T ₁ ), as shown in Figure 11 may not completely match the waveform of the resonant current of FIG.

As a result, the DC-DC converter of FIG. 10 applies an interleaved half-wave current resonant converter differently from the DC-DC converter of FIG. 4, but similarly to the DC-DC converter of FIG. input voltage (V _in) to increase the voltage level of the output direct voltage (V _o) when the lower can perform an operation for stabilizing the output voltage _{(V o = V o1 + V} o2).

On the other hand, since the configuration of the output terminal of the DC-DC converter of FIG. 11 is the same as that of the output terminal of the DC-DC converter of FIG. In addition, since the operation waveform of the DC-DC converter of FIG. 11 is similar to that of the DC-DC converter of FIG. 10, it will not be described separately.

13 and 14 show another example of the DC-DC converter according to the present invention.

The DC-DC converter of FIG. 13 has almost the same configuration as the DC-DC converter of FIG. 11, but the LLC resonant converter is implemented as a full bridge LLC resonant converter. The DC-DC converter of FIG. 13 is similar to the DC-DC converter of FIG. 9 between the input node N _in and the first ground node N _G1 instead of the first and second resonant capacitors C _r1 and C _r2 . And a second switching unit having third and fourth switch elements S ₃ and S ₄ connected in series. That is, the DC-DC converter of FIG. 13 is a DC-DC converter configured by combining an interleaved half-wave current resonant converter and a full bridge LLC resonant converter. Since the operation of the interleaved half-wave current resonant converter and the operation of the full bridge LLC resonant converter have been described with reference to FIGS. 11 and 9, detailed descriptions thereof are omitted here.

FIG. 14 shows that the DC-DC converter according to the present invention can be combined with various half-wave resonant converters and LLC resonant converters. The DC-DC converter of FIG. 13 is interleaved half-wave at one end of the main resonance input unit which is a full bridge LLC resonant converter. In contrast to the input part of the current resonant converter, in FIG. 14, the input parts of the half-wave current resonant converter are coupled to both ends of the main resonant input part implemented as a full bridge LLC resonant converter.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (26)

A voltage input corresponding to a current change of the first winding end of the resonant transformer, connected to a resonant input unit which receives an input voltage and induces a current change in the first winding end of the resonant transformer, and a second winding end of the resonant transformer. A main converter having a resonant output for rectifying and then generating an output voltage; And
An auxiliary input unit connected in parallel with the resonance input unit with respect to the input voltage, and an auxiliary output unit connected in series with the resonance output unit with respect to the output voltage, wherein a voltage level of the input voltage is higher than a specified reference voltage. An auxiliary converter which is activated when low and raises the voltage level of the output voltage generated in the main converter,
The auxiliary converter
And when the input voltage is lower than the reference voltage, is activated in response to the voltage level of the input voltage to increase the voltage level of the output voltage.
delete The method of claim 1, wherein the main converter
DC-DC converter, characterized in that the LLC resonant converter.
The method of claim 3, wherein the resonant input unit
A switching unit having first and second switch elements connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input voltage;
A resonator unit connected to the switching unit in parallel and having first and second resonant capacitors connected in series between the input node and the first ground node; And
And said first winding end of said resonant transformer connected between a first conversion node between said first and second switch elements and a second conversion node between said first and second resonant capacitors. -DC converter.
The method of claim 4, wherein the first and second switch element
The DC-DC converter, which is activated in response to the first and second switching signals applied at a fixed ratio, respectively, to perform zero voltage switching.
The method of claim 3, wherein the resonant input unit
A first switching unit including first and second switch elements connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input voltage;
A second switching unit connected in parallel with the switching unit and having third and fourth switch elements connected in series between the input node and the first ground node; And
The first winding end of the resonant transformer and a resonant capacitor connected in series between a first conversion node between the first and second switch elements and a second conversion node between the third and fourth switch elements; DC-DC converter, characterized in that.
The method of claim 6, wherein the first to fourth switch element
The DC-DC converter, which is activated in response to the first and second switching signals applied at a fixed ratio, respectively, to perform zero voltage switching.
The method of claim 5, wherein the resonance output unit
A first second winding end of the resonant transformer and a first output diode connected in series between a first output node to which the output voltage is output and a second output node to which one end of the auxiliary converter is connected; A resonance output unit;
A second resonant output having a second second winding end and a second output diode of the resonant transformer connected in series between the first and second output nodes in parallel with the first resonant output; And
And an output capacitor connected in parallel with the first and second resonant outputs between the first and second output nodes.
The method of claim 5, wherein the resonance output unit
DC-DC converter, characterized in that implemented as a single bridge rectifier for rectifying the current induced in the second winding end of the resonant transformer.
The method of claim 5, wherein the resonance output unit
DC-DC converter, characterized in that implemented as a doubler rectifier for rectifying the current induced in the second winding end of the resonant transformer.
The method of claim 8, wherein the auxiliary converter
DC-DC converter characterized in that the interleaved flyback converter.
The method of claim 11, wherein the auxiliary input unit
A first flyback input having a first winding end and a first flyback switch element of a first flyback transformer connected in series between the input node and the first ground node; And
A second fly fly connected in parallel with the first flyback input and having a first winding end and a second flyback switch element of a second flyback transformer connected in series between the input node and the first ground node; DC-DC converter comprising a back input unit.
The method of claim 12, wherein the auxiliary output unit
A first flyback output having a third output diode connected in series between the second output node and a second ground node and a second winding end of a first flyback transformer;
A second flyback output having a second winding end of a fourth output diode and a second flyback transformer connected in series between the second output node and the second ground node; And
And a flyback output capacitor section having a flyback output capacitor and a fifth output diode connected between the second output node and the second ground node.
The method of claim 8, wherein the auxiliary converter
DC-DC converter, characterized in that it is one of a single flyback converter, push-pull converter, forward converter and full-bridge converter.
The main resonance input unit which receives an input voltage and induces a current change in the first winding end of the resonant transformer and is activated when the voltage level of the input voltage is lower than the predetermined reference voltage, respectively, and the first and second half-wave current resonant transformers, respectively. An input stage having an interleaved half-wave current resonant input unit for alternately inducing a current change in the first winding stage of the circuit; And
A resonant output unit and a first half wave current connected to a second winding end of the resonant transformer to generate a voltage corresponding to a voltage change of the first winding end of the resonant transformer, and then rectify and generate an output voltage; And an output stage connected to the second winding end of the resonant transformer and including a half-wave current resonant output unit for raising a voltage level of the output voltage generated in the resonant output unit.
The method of claim 15, wherein the main resonance input unit
A switching unit having first and second switch elements connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input voltage;
A resonator unit connected to the switching unit in parallel and having first and second resonant capacitors connected in series between the input node and the first ground node; And
And said first winding end of said resonant transformer connected between a first conversion node between said first and second switch elements and a second conversion node between said first and second resonant capacitors. -DC converter.
The method of claim 16, wherein the interleaved half-wave current resonant input unit
A first half wave switch element and a first half wave diode connected in series between the input node and the first ground node, and a third conversion node and the first conversion between the first half wave switch element and the first half wave diode. A first half wave current resonant input having a first winding end and a first half wave current resonant capacitor of the first half wave current resonant transformer connected in series between nodes; And
A second half wave diode and a second half wave switch element connected in series between the input node and the first ground node, a fourth conversion node and the first conversion node between the second half wave diode and the second half wave switch element. And a second half-wave current resonant input having said first winding end and a second half-wave current resonant capacitor of said second half-wave current resonant transformer connected in series therebetween.
The method of claim 16, wherein the interleaved half-wave current resonant input unit
And a first half-wave current resonant capacitor and a first half-wave switch element of the first half-wave current resonant transformer connected in series between the first conversion node and the first ground node. A first half wave current resonant input having a third resonant diode connected between the current resonant capacitor and the first half wave switch element and the first conversion node; And
The second half-wave current resonant capacitor and a second half-wave current resonant capacitor of the second half-wave current resonant transformer connected in series between the input node and the first conversion node; And a second half-wave current resonant input having a second resonant diode connected between the capacitor and a fourth conversion node between the second half-wave switch element and the input node.
The method of claim 17, wherein the resonance output unit
A first second winding end of the resonant transformer and a first output diode connected in series between a first output node to which the output voltage is output and a second output node to which one end of the half-wave current resonant output part is connected; A first resonance output unit;
A second resonant output having a second second winding end and a second output diode of the resonant transformer connected in series between the first and second output nodes in parallel with the first resonant output; And
And an output capacitor connected in parallel with the first and second resonant outputs between the first and second output nodes.
The method of claim 19, wherein the half-wave current resonance output unit
A first half-wave resonant output having a third output diode connected in series between the second output node and a second ground node and a second winding end of the first half-wave resonant transformer;
A second half-wave resonant output having a fourth output diode connected in series between the second output node and the second ground node and a second winding end of the second half-wave resonant transformer; And
And a half-wave resonant output capacitor unit having a half-wave resonant output capacitor and a fifth output diode connected between the second output node and the second ground node.
The method of claim 15, wherein the main resonance input unit
A first switching unit including first and second switch elements connected in series between an input node connected to one end of the input voltage and a first ground node connected to the other end of the input voltage;
A second switching unit connected in parallel with the first switching unit and having third and fourth switch elements connected in series between the input node and the first ground node; And
And a first winding end of the resonant transformer and a resonant capacitor connected between a first conversion node between the first and second switch elements and a second conversion node between the third and fourth switches. DC-DC converter.
The method of claim 21, wherein the interleaved half-wave current resonant input unit
And a first half-wave current resonant capacitor and a first half-wave switch element of the first half-wave current resonant transformer connected in series between the first conversion node and the first ground node. A first half wave current resonant input having a third resonant diode connected between the current resonant capacitor and the first half wave switch element and the first conversion node; And
The second half-wave current resonant capacitor and a second half-wave current resonant capacitor of the second half-wave current resonant transformer connected in series between the input node and the first conversion node; And a second half-wave current resonant input having a second resonant diode connected between the capacitor and a fourth conversion node between the second half-wave switch element and the input node.
The method of claim 22, wherein the interleaved half-wave current resonant input unit
And a third and fourth half-wave current resonant transformer, and inducing current change alternately at first winding ends of each of the first to fourth half-wave current resonant transformers.
The method of claim 23, wherein the interleaved half-wave current resonant input unit
A third half wave current resonant capacitor and a third half wave switch element of the third half wave current resonant transformer connected in series between the second conversion node and the first ground node; A third half-wave current resonant input having a fifth resonant diode connected between the current resonant capacitor and the third half-wave switch element and the second converted node; And
And a fourth half-wave current resonant capacitor and a fourth half-wave switch element of the fourth half-wave current resonant transformer connected in series between the input node and the second conversion node, and the fourth half-wave current resonator. And a fourth half-wave current resonant input having a sixth conversion node between the capacitor and the fourth half-wave switch element and a fourth resonant diode connected between the input node.
The method of claim 22, wherein the resonant output unit
A first second winding end of the resonant transformer and a first output diode connected in series between a first output node to which the output voltage is output and a second output node to which one end of the half-wave current resonant output part is connected; A first resonance output unit;
A second resonant output having a second second winding end and a second output diode of the resonant transformer connected in series between the first and second output nodes in parallel with the first resonant output; And
And an output capacitor connected in parallel with the first and second resonant outputs between the first and second output nodes.
The method of claim 25, wherein the half-wave resonant current output unit
A first half-wave resonant output having a third output diode connected in series between the second output node and a second ground node and a second winding end of the first half-wave resonant transformer;
A second half-wave resonant output having a fourth output diode connected in series between the second output node and the second ground node and a second winding end of the second half-wave resonant transformer; And
And a half-wave resonant output capacitor unit having a half-wave resonant output capacitor and a fifth output diode connected between the second output node and the second ground node.

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