JP2004015941A - Positive/negative dc power supply unit and semiconductor testing device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor testing device having a positive/negative DC power supply unit and capable of shifting both output voltages of positive and negative power supplies, by eliminating the need for a DC-DC converter for an exclusive voltage shift, in an individual I/F circuit mounted on a performance board. <P>SOLUTION: This positive/negative DC power supply unit includes an isolated DC power supply. The DC power supply has a primary side and a secondary side for supplying the power isolated from each other, and delivers the positive/negative DC power supplies from the secondary side. With three output terminals of the DC power supply on the secondary side taken as a positive output terminal for supplying positive voltage, a negative output terminal for supplying negative voltage, and a common terminal COM of the positive and negative output terminals; the positive terminal and the negative terminal are connected to a load device, and are inserted in between a circuit ground GND of the load device and the common terminal COM to provide a voltage shift means of applying a predetermined voltage drop. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a positive / negative DC power supply that can shift output voltages of both positive and negative power supplies in a DC power supply that supplies positive and negative power supplies. In particular, the present invention relates to a semiconductor test apparatus provided with a positive / negative DC power supply that can shift an output voltage of a positive / negative power supply supplied to the interface circuit when mounting an interface circuit corresponding to a type of DUT provided on a performance board of the semiconductor test apparatus. .
[0002]
[Prior art]
FIG. 7 is a conceptual diagram of a test head of a semiconductor test device. A dedicated performance board PB corresponding to the DUT is mounted on the test head, and various tests of the DUT are performed. Here, since the semiconductor test apparatus is well-known and well-known in the art, other signals and components, and the detailed description thereof will be omitted except for the main part according to the present application.
[0003]
The performance board PB includes, for example, a cable for signal connection with the pin electronics side, a contactor (such as an IC socket) for contacting one or more DUTs, an individual I / F circuit 100, and other circuits. ing.
[0004]
The individual I / F circuit 100 implements an interface circuit for each DUT in a case where the test cannot be performed with the hardware resources of the pin electronics provided in the test head. However, since it is on a performance board, the area of the interface circuit that can be mounted is finite and narrow, and the available DC power supply is also limited.
By the way, the DC power supply used for the DUT-specific interface circuit may require a DC power supply other than the 5v and 12v power supplies supplied from the test head. In this case, it becomes necessary to provide a DC power supply on the performance board.
[0005]
Next, FIG. 1A shows a conventional configuration example of a DC power supply unit required by the individual I / F circuit 100 shown in FIG. Here, it is assumed that a specific example of generating + 12v and -18v obtained by shifting the voltage by -3v with respect to the DCDC converter of ± 15v. Also, it is assumed that the individual I / F circuit 100 mainly forms an interface circuit including an operational amplifier circuit. Note that an actual semiconductor test apparatus has a plurality of similar circuit configurations corresponding to the number of DUTs.
[0006]
1 includes DCDC converters DCDC1 and DCDC2, and a load circuit RL.
The DCDC converter DCDC1 is an insulation type DCDC converter, and supplies a current of several hundred mA at a DC voltage of ± 15 V.
[0007]
The DCDC converter DCDC2 is a voltage shift means for applying a shift voltage V3 to both voltages of ± 15 V, and generates a DC voltage of −3 V as an example.
[0008]
In these connections, the COM terminal on the output side of the DCDC converter DCDC1 is connected to the -3v terminal of DCDC2 as shown in FIG. The COM terminal on the output side of the DCDC converter DCDC2 is connected to the circuit ground GND. As a result, the positive voltage V1 is shifted by -3v and supplied to one end of the load circuit RL1 as a voltage of + 12v, and the negative voltage V2 is shifted by -3v and supplied to the other end of the load circuit RL2 as a voltage of -18v.
[0009]
The load circuit RL is an interface circuit that interfaces with a DUT on a performance board. As an example, there is an interface circuit that amplifies an AC signal by an operational amplifier circuit. Although not shown, a bypass capacitor having a desired capacitance is connected between the positive voltage V1 and the negative voltage V2 and the circuit ground.
[0010]
FIG. 1B is a circuit example when a voltage shift is required for a DC power supply used in an operational amplifier circuit. For example, the input signal Vin output from the DUT is an AC signal of 50 mV in a state in which a DC voltage of -12v to 0v is superimposed, and the operational amplifier circuit serving as an interface circuit receives the AC signal and amplifies the input signal by, for example, 100 times. Output a signal. At this time, the required positive and negative power supplies are required to supply a DC power supply that can amplify the input signal and the output signal with high linearity.
[0011]
Here, in a circuit having a configuration such as an operational amplifier circuit, a small amount of current flows to the circuit ground GND. Therefore, the current i1 flowing through one load circuit RL1 and the current i2 flowing through the other load circuit RL2 are almost the same. Accordingly, the GND current iGND flowing to the COM terminal of the DCDC converter DCDC1 is small. For example, when the current i1 is 100 mA, the GND current iGND is a small current of several mA or less.
[0012]
According to the above-described conventional configuration, it is necessary to provide the DCDC converter DCDC2 as the voltage shift means. DCDC converters require a relatively large mounting space. On the other hand, considering that the DC power supply unit is mounted together with other interface circuits on a performance board PB having a finite space, it is desired that the mounting space of the DC power supply unit be reduced as much as possible. Further, a voltage value of a different voltage shift may be required depending on the type of DUT. The allowable power supply fluctuation of the DC power supply is generally about ± 90 dB because the power supply fluctuation rejection ratio PSRR of the operational amplifier is about ± 90 dB.
[0013]
[Problems to be solved by the invention]
As described above, in the related art, in order to supply a positive / negative power supply that is shifted in voltage corresponding to the type of DUT, a DCDC converter dedicated to voltage shifting is provided.
Incidentally, there are many cases where the load circuit RL is an interface circuit such as an operational amplifier circuit in which a small amount of current flows to the circuit ground GND.
The DCDC converter dedicated to the voltage shift has a disadvantage that a relatively large mounting space is required on the finite space performance board PB. Further, with the mounting of the DCDC converter dedicated to the voltage shift, other interface circuits may be subject to mounting restrictions.
Therefore, an object of the present invention is to provide a positive / negative DC power supply device capable of shifting both output voltages of positive and negative power supplies in an individual I / F circuit provided on a performance board without the need for a DCDC converter dedicated to voltage shift. It is to provide a semiconductor test device.
Another object of the present invention is to provide a positive / negative DC power supply device for supplying a positive / negative power supply that does not require a DCDC converter dedicated to voltage shift.
[0014]
[Means for Solving the Problems]
A first solution is shown. Here, FIG. 2 and FIG. 3 show a solution according to the present invention.
In order to solve the above-mentioned problem, an insulated DC power supply (for example, DCDC1) is provided. The DC power supply is insulated from a primary side and a secondary side for supplying power, and a positive / negative DC power supply is provided from a secondary side. That supplies
The three output terminals on the secondary side of the DC power supply are a positive output terminal for supplying a positive voltage, a negative output terminal for supplying a negative voltage, and a common output terminal COM when the positive and negative output terminals are referred to as a positive output terminal. And the negative output terminal are connected to a load device (load circuit RL),
A positive / negative DC power supply device comprising: a voltage shift unit that is inserted between a circuit ground GND of a load device and a common terminal COM to give a predetermined voltage drop.
According to the above invention, a DC / DC converter dedicated to voltage shift is not required, and a positive / negative DC power supply device capable of shifting both output voltages of the positive and negative power supplies can be realized.
[0015]
Next, a second solution will be described. Here, FIGS. 2 and 6 (b) show a solution according to the present invention.
One embodiment of the voltage shift means 30 includes a first diode (forward series diode D1) in which a plurality of the diodes are connected in series so as to have a predetermined voltage drop.
A second diode (reverse diode D2) connected in anti-parallel with the first diode;
A first diode connected between a positive output terminal or a negative output terminal of an insulated DC power supply and a circuit ground GND of a load device to prevent a change in the amount of current flowing to the circuit ground GND due to a current change in the load device. Comprises a resistor R1 for flowing a predetermined bias current to the first diode so that the current does not enter a no-current state,
The power supply voltage supplied from both the positive output terminal and the negative output terminal to the load device is connected to the negative side or the positive side based on the connection direction of the first diode and the connection condition of the resistor R1. There is the above-mentioned positive / negative DC power supply device characterized in that the voltage is shifted.
[0016]
Next, a third solution will be described. Here, FIG. 4 (a) shows a solution according to the present invention.
One mode of the voltage shift means 30b includes a Zener diode ZD1 exhibiting a Zener voltage characteristic that causes a predetermined voltage drop,
The zener diode ZD1 is connected between the positive output terminal or the negative output terminal of the insulated DC power supply and the circuit ground GND of the load device, and the Zener diode ZD1 responds to a change in the amount of current flowing to the circuit ground GND due to a current change of the load device. A resistor R1 for flowing a predetermined bias current that does not enter a no-current state to the Zener diode ZD1;
The power supply voltage supplied from both the positive output terminal and the negative output terminal to the load device is supplied to the negative side or the positive side based on the connection direction of the Zener diode ZD1 and the connection condition of the resistor R1. There is the above-described positive / negative DC power supply device that performs voltage shift.
[0017]
Next, a fourth solution will be described. Here, FIG. 4 (b) shows a solution according to the present invention.
The voltage shift means 30b further includes a second diode (reverse diode D2) connected in anti-parallel to the zener diode ZD1.
[0018]
Next, a fifth solution will be described. Here, FIG. 5 shows a solution according to the present invention.
One embodiment of the voltage shift means 30d includes a variable constant voltage circuit VZ3 which exhibits a predetermined voltage drop characteristic and externally changes the voltage to be dropped.
A variable constant voltage circuit which is connected between a positive output terminal or a negative output terminal of an insulated DC power supply and a circuit ground GND of a load device to prevent a change in the amount of current flowing to the circuit ground GND due to a current change of the load device. A resistor R1 that allows a predetermined bias current that does not cause VZ3 to enter a no-current state to flow to the variable constant voltage circuit VZ3;
A second diode (reverse diode D2) connected in antiparallel with the variable constant voltage circuit VZ3;
The power supply voltage supplied from both the positive output terminal and the negative output terminal to the load device is connected to the negative side or the positive side based on the connection direction of the variable constant voltage circuit VZ3 and the connection condition of the resistor R1. The positive / negative DC power supply described above is characterized in that the voltage is shifted to the side.
[0019]
Next, a sixth solution will be described. Here, FIG. 6 (a) shows a solution according to the present invention.
In the voltage shift means 30, 30b, 30c, 30d, a capacitor C1 for bypassing an AC component is connected in parallel to both ends of the voltage shift means to bypass AC components such as low frequency and high frequency signals. There are positive and negative DC power supplies.
[0020]
Next, a seventh solution will be described. Here, FIG. 7 shows a solution according to the present invention.
There is a semiconductor test apparatus characterized in that at least one channel of the above-described positive / negative DC power supply device is provided on a performance board PB mounted on a test head included in the semiconductor test apparatus.
Thereby, the DCDC converter dedicated to the voltage shift can be eliminated.
[0021]
The means of the present invention may be practicable other constituent means by appropriately combining the respective element means in the above-mentioned solving means, if desired. Further, although the reference numerals given to the respective elements correspond to the reference numerals shown in the embodiments of the invention, the present invention is not limited to these, and other practical equivalents are applied. It is good.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example of an embodiment to which the present invention is applied will be described with reference to the drawings. Further, the scope of the claims is not limited by the following description of the embodiments, and the elements, connection relationships, and the like described in the embodiments are not necessarily essential to the solution. Furthermore, the descriptions / forms of the elements, connection relations, and the like described in the embodiments are merely examples, and are not limited to the descriptions / forms.
[0023]
The present invention will be described below with reference to FIGS. Elements corresponding to those in the conventional configuration are denoted by the same reference numerals, and description of overlapping parts is omitted.
[0024]
FIG. 2 shows a first configuration example of the DC power supply unit required by the individual I / F circuit 100. FIG. 3 is a diagram for explaining the operation of the voltage shift. Here, it is assumed that FIG. 2 is a specific example in which +12 V and −18 V are shifted by −3 V with respect to a DC / DC converter of ± 15 V as in the related art.
This component includes a DCDC converter DCDC1, voltage shift means 30, and a load circuit RL.
[0025]
The voltage shift means 30 is a voltage shift means for shifting both voltages of ± 15 V to the negative side by a desired shift voltage V3, and shifts a DC voltage of about −3 V as an example. This internal element comprises a forward series diode D1, a reverse diode D2, and a resistor R1.
[0026]
The forward series diode D1 is formed by connecting a plurality of diodes that provide a voltage drop that provides a desired shift voltage V3 in series. For example, assuming a voltage drop of 0.6 V per diode, to provide a voltage drop VD1 of about 3 V, 3 V / 0.6 V ≒ 5 diodes are connected in series.
[0027]
The reverse diode D2 is a protection diode that allows a reverse pulse current to pass. However, in most cases, the bias current of the resistor R1 is set so that such a reverse current does not occur.
[0028]
The resistor R1 supplies a desired bias current iR1 to the forward series diode D1 to give a voltage drop of about 3V. The amount of the bias current iR1 is, for example, about twice or more the maximum value or the pulse current of the GND current iGND, which is a possible imbalance current between the current i1 and the current i2 flowing through the load circuit RL. Flow. As an example, when the maximum value of the GND current iGND is 5 mA, a resistance value of 1.2 KΩ which becomes the bias current iR1 of 10 mA is used.
FIG. 3A is a diagram showing the relationship between the common terminal current iCOM and the practical range with respect to the GND current iGND accompanying the application of the bias current iR1, and FIG. 3B is a diagram showing the relationship between the shift voltage V3 and the practical range with respect to the common terminal current iCOM. It is. These relationship diagrams will be described.
In FIG. 3A, when the GND current iGND is less than the bias current iR1 of 10 mA (see FIG. 3A), the forward series diode D1 is in an active state because the common terminal current iCOM flows. Therefore, as a result of maintaining the voltage drop VD1 of about 3 V by the forward series diode D1, a usable practical range is obtained within this range (see FIG. 3B).
[0029]
In FIG. 3B, in the practical range of the common terminal current iCOM in the forward direction current (see FIG. 3G), a voltage drop VD1 of about 3 V is obtained by the forward series diode D1, resulting in the common terminal of the DCDC converter DCDC1. COM is maintained at -3v. Therefore, the −15 V negative output terminal side of the DCDC converter DCDC 1 is equivalent to a power generation of −15 V + (− 3 V) = − 18 V with respect to the circuit ground GND. Conversely, the + 15V positive output terminal side of the DCDC converter DCDC1 is equivalent to a power supply generation of + 15V + (-3V) = + 12V with respect to the circuit ground GND.
Incidentally, if the common terminal current iCOM is in the negative current state (see FIG. 3E), it becomes about +0.6 V due to the reverse diode D2. In this case, the intended voltage shift of -3v is not achieved.
[0030]
According to the configuration example of FIG. 2 described above, the configuration including the voltage shift means 30 provides a great advantage that a DCDC converter DCDC2 dedicated to voltage shift as in the related art becomes unnecessary. Further, there is an advantage that the DC power supply unit provided on the performance board can be reduced in size to about 1/2.
[0031]
Next, FIG. 4A illustrates a second configuration example of the DC power supply unit required by the individual I / F circuit 100. In this configuration, the internal components of the voltage shift means 30b are configured to provide a desired voltage drop by the resistor R1 and one zener diode ZD1. Incidentally, as shown in the internal configuration example of the voltage shift means 30c in FIG. 4B, a configuration may be adopted in which a reverse diode D2 is additionally provided.
[0032]
The zener diode ZD1 uses a zener voltage of 3V. In addition, with respect to the current in the reverse direction, the diode characteristic of the Zener diode can protect the pulse current in the reverse direction from passing. This configuration example also provides a great advantage that a DCDC converter DCDC2 dedicated to voltage shift as in the related art is not required. Further, there is obtained an advantage that the power supply unit provided on the performance board can be miniaturized most.
[0033]
Next, FIG. 5 shows a third configuration example of the DC power supply unit required by the individual I / F circuit 100. In this configuration, the internal components of the voltage shift unit 30d include a resistor R1, a variable constant voltage circuit VZ3, and a reverse diode D2.
[0034]
The variable constant voltage circuit VZ3 has a function of varying the voltage to be shifted. As an example of the internal configuration, as shown in FIG. 5B, the variable constant voltage circuit VZ3 includes a variable resistor VR3 and a transistor Q3.
The transistor Q3 functions as a 3V Zener diode when the setting of the variable resistor VR3 is set to a middle point position when the gate voltage is turned on at, for example, 1.5 V or more. Therefore, by adjusting the setting of the variable resistor VR3, there is obtained an advantage that the variable resistor VR3 can function as a variable zener diode that can be changed to, for example, about 1.5 V to 10 V. As a result, when it is necessary to supply a DC power supply having a different voltage shift for each type of DUT, it is possible to obtain the convenience of adjusting the voltage shift conditions to the optimum conditions.
[0035]
Next, FIG. 6A shows a fourth configuration example of the DC power supply unit required by the individual I / F circuit 100. In this configuration, a capacitor C1 is connected between the common terminal COM of the above-described voltage shift means 30 to 30d and the circuit ground GND.
The capacitor C1 is for bypassing AC components such as low-frequency and high-frequency signals generated at both ends. For example, an electrolytic capacitor of about 100 μF and a ceramic capacitor of about 1 μF are used in parallel. Thus, the internal impedance of the power supply side for the AC signal can be reduced.
[0036]
It should be noted that the technical idea of the present invention is not limited to the specific configuration examples and connection examples of the above-described embodiment. Furthermore, based on the technical idea of the present invention, the above-described embodiment may be appropriately modified and widely applied.
For example, in the above-described embodiment, a specific example in which the output voltage of the positive and negative power supplies to be supplied is shifted by −3V to the negative side, but as shown in FIG. By doing so, a + 3v shift to the positive side can be realized. Therefore, it is possible to supply a positive / negative power supply whose voltage is desirably shifted in accordance with the interface circuit corresponding to the type of DUT.
[0037]
In addition, the amount of the bias current iR1 may be set to a sufficiently large amount of current corresponding to the maximum GND current iGND assumed in the interface circuit to be applied. Therefore, the present invention can be applied to circuits other than the operational amplifier circuit as the interface circuit.
[0038]
Further, in the above-described embodiment, the specific example in which the semiconductor device is provided on the performance board of the semiconductor test device has been described. However, there is no large variation of the GND current iGND, and the power supply variation of about ± 0.3 V can be tolerated. Even in such a case, the DC power supply unit for shifting the output voltage of the positive and negative power supplies of the present invention can be applied.
[0039]
【The invention's effect】
The present invention has the following effects based on the above description.
As described above, according to the present invention, the configuration including the voltage shift means for shifting the voltage of the positive and negative DC power supplies provides a great advantage that the DCDC converter DCDC2 dedicated to the conventional voltage shift is not required. . Further, there is an advantage that the power supply unit provided on the performance board can be reduced in size. In addition, when simultaneously measuring a plurality of DUTs such as four or eight, there is obtained an advantage that a DC power supply of a plurality of channels can be practically mounted on a performance board together with an interface circuit. There is also an advantage that the DC power supply unit can be configured at low cost.
Therefore, the technical effect of the present invention is great, and the industrial economic effect is also great.
[Brief description of the drawings]
FIG. 1 is a configuration example of a conventional DC power supply unit required by an individual I / F circuit 100;
FIG. 2 is a first configuration example of a DC power supply unit required by an individual I / F circuit 100;
FIG. 3 is a diagram showing a relationship between a common terminal current iCOM and a practical range with respect to a GND current iGND accompanying application of a bias current iR1, and a diagram showing a relationship between a shift voltage V3 and a practical range with respect to a common terminal current iCOM.
FIG. 4 is a second configuration example of a DC power supply unit required by the individual I / F circuit 100;
FIG. 5 is a third configuration example of the DC power supply unit required by the individual I / F circuit 100;
FIG. 6 shows a fourth configuration example of the DC power supply unit required by the individual I / F circuit 100 and a configuration example in the case of shifting the voltage to the positive side.
FIG. 7 is a conceptual diagram of a test head of the semiconductor test device.
[Explanation of symbols]
C1 Capacitor D1 Forward series diode DCDC1, DCDC2 DCDC converter R1 Resistance RL1, RL2, RL Load circuit ZD1 Zener diode D2 Reverse diode Q3 Transistor VR3 Variable resistance VZ3 Variable constant voltage circuit 30, 30b, 30c, 30d Voltage shift means 100 Individual I / F circuit DUT Device under test PB Performance board

Claims (7)

An insulated DC power supply is provided, wherein the DC power supply is configured such that a primary side and a secondary side for supplying power are insulated from each other, and supplies positive and negative DC power from the secondary side.
The three output terminals on the secondary side of the DC power supply are a positive output terminal for supplying a positive voltage, a negative output terminal for supplying a negative voltage, and a common output terminal COM when the positive and negative output terminals are referred to as a common output terminal. Terminal and the negative output terminal are connected to the load device,
A positive / negative DC power supply device comprising: voltage shift means for inserting a predetermined voltage drop between a circuit ground GND of a load device and the common terminal COM. The voltage shift means includes a first diode in which a plurality of diodes are connected in series so as to have a predetermined voltage drop;
A second diode connected in anti-parallel to the first diode;
A resistor connected between the positive output terminal or the negative output terminal of the insulated DC power supply and the circuit ground GND of the load device and flowing a predetermined bias current to the first diode;
The power supply voltage supplied from both the positive output terminal and the negative output terminal to the load device is supplied to the negative side or the positive side based on the connection direction of the first diode and the connection condition of the resistor. 2. The positive / negative DC power supply according to claim 1, wherein the shift is performed. The voltage shift means includes a Zener diode that causes a predetermined voltage drop,
A resistor connected between the positive output terminal or the negative output terminal of the insulated DC power supply and the circuit ground GND of the load device to flow a predetermined bias current through the Zener diode;
And shifts both power supply voltages supplied to the load device from both the positive output terminal and the negative output terminal to the negative side or the positive side based on the connection direction of the Zener diode and the connection condition of the resistor. 2. The positive / negative DC power supply according to claim 1, wherein: 4. The positive / negative DC power supply device according to claim 3, further comprising a second diode connected in anti-parallel to said Zener diode. The voltage shift means has a predetermined voltage drop characteristic, and a variable constant voltage circuit that externally changes a voltage to be dropped,
A resistor connected between the positive output terminal or the negative output terminal of the insulated DC power supply and the circuit ground GND of the load device to flow a predetermined bias current to the variable constant voltage circuit;
A second diode connected in antiparallel with the variable constant voltage circuit;
The power supply voltage supplied from both the positive output terminal and the negative output terminal to the load device is supplied to the negative side or the positive side based on the connection direction of the variable constant voltage circuit and the connection condition of the resistor. 2. The positive / negative DC power supply according to claim 1, wherein the shift is performed. 6. The positive / negative DC power supply device according to claim 1, further comprising a capacitor connected in parallel between both ends of said voltage shift means for bypassing an AC component. 7. A semiconductor test apparatus comprising at least one channel of the positive / negative DC power supply according to claim 1 on a performance board PB mounted on a test head included in the semiconductor test apparatus.

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