JPH09178781A - Device for measuring voltage application current - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current measuring device where the power capacity of an output voltage control circuit is reduced. SOLUTION: A peak current side path circuit means 800 for bypassing peak current after being connected to a current detection means 70 for measuring current is configured in inverse parallel connection of a peak current side path circuit 810 and a peak current side path circuit 820. Then, a plurality of constant current sources 15 and 16 for flowing bias current to a plurality of diodes D1-D8 of the peak current side path circuit means 800 being equal to a reference VM1 voltage converted by the current detection means 70 for measuring current are provided for controlling with the sum of a plurality of diodes VF being equal to the reference VM1 voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage applied current measuring device that can be used in the technical field of IC test systems.

[0002]

2. Description of the Related Art A test for a semiconductor under test includes a functional test for testing whether the semiconductor under test performs a predetermined operation,
There is a DC test that tests whether the semiconductor under test has the specified DC characteristics. When performing a functional test of the semiconductor under test, a predetermined power supply voltage is applied to the power supply terminal of the semiconductor under test and the current flowing during operation is measured. In the DC characteristic test, a predetermined voltage is applied to the input / output terminals of the semiconductor under test and the current flowing at that time is measured.
For example, a DC test with a current of several nA to several mA and 5
There is a functional test that flows from 00 mA to 800 mA. (Reference material: Jikken 6-11510 Device name: Voltage applied current measuring device)

FIG. 5A shows a voltage applied current measuring device according to the prior art, and FIG. 5B shows a diode current characteristic in the peak current bypass circuit means. Semiconductor under test (hereinafter DU
The output voltage control circuit 10 for supplying a predetermined voltage to (T) is composed of an operational amplifier 11 and a voltage setter 12. The output voltage of the output voltage control circuit 10 is used for current measurement by the current detection means 110 and the range switching means 72 formed by a plurality of series circuits including resistors and switches in parallel with the resistors of the current measurement current detection circuit 71. The current detecting means 70 and a series diode in which diodes are connected in anti-parallel, that is, a plurality of diodes in a forward connection are used as a peak current bypass circuit 81, and a series diode in which a plurality of diodes are connected in a forward direction is used as a peak current bypass circuit. Circuit 8
2, the peak current bypass circuit means 8 connected in anti-parallel to 2
0, and the peak current bypass circuit means 80 can bypass the peak current of the DUT regardless of the resistor of the current measuring current detection circuit 71.

The peak current bypassed from the peak current bypass circuit means 80 is converted into a voltage by the current limiting current detecting resistor 40, and the voltage is taken out by the current limiting differential amplifier 50 and controlled for current limiting. When the peak current exceeds the set value of the limiting current, the current limiting control circuit 60 outputs the current limiting control current I1 to the output voltage control circuit 10 to control the test voltage Vo. The voltage at the terminal of the DUT is taken out by the voltage feedback circuit 20 by the amplifier 21 having a high input impedance, and the output voltage is fed back to the input terminal of the operational amplifier 11 constituting the output voltage control circuit 10. Due to the presence of the voltage feedback circuit 20, the operational amplifier 11 operates so that the voltage given from the voltage setting circuit 12 and the voltage fed back from the voltage returning circuit 20 become equal, whereby the voltage setting circuit 12 is fed to the terminal of the DUT. It operates to give a voltage equal to the given voltage value.

The resistance value of the resistor of the current measuring current detecting means 70 is equal to the resistance value of the resistor of the current limiting current detecting resistor 40.
1,000 times to 10,000 times. For example, the current limiting current detection resistor 40 is several Ω, and the resistance values of the current measuring current detection circuit 71 and the range switching means 72 are several tens Ω to several hundreds KΩ. For example, a current of a direct current test for testing whether the direct current characteristic of the DUT has been completed to a specified characteristic is several nA to several mA. The voltage V converted from current to voltage by the current measuring current detection circuit 71 and the range switching means 72
M1 is taken out by the differential amplifier 90 for current measurement and AD
This is a configuration in which the converter 100 converts it into a digital signal and treats it as a current measurement value.

When performing a functional test of the DUT, a current of 500 mA to 800 mA, for example, flows during operation by applying a predetermined power supply voltage to the power supply terminal of the DUT. DT
The operating current flowing in U flows into the current limiting current detecting resistor 40 through the peak current bypass circuit means 80, and is converted into a voltage by the current limiting current detecting resistor 40. The output voltage control circuit 1 is extracted by the amplifier 50 and is output by the current limiting control circuit 60.
The output voltage Vo of 0 is forcibly controlled to limit the current flowing through the DUT. In the current limiting control circuit 60, when the transient current exceeds the set value of the limiting current, the output voltage control circuit 1
The current I1 for current limiting is output to 0 to control the output voltage Vo.

The current of the DC test is, for example, several nA to several mA.
In the test in which the current flows, the current is not allowed to flow in the peak current bypass circuit means 80 from the viewpoint of measurement accuracy. FIG. 5B shows the diode current characteristic in the peak current bypass circuit means. The peak current side current is shown on the Y axis and the VM1 voltage is shown on the X axis. Peak current bypass circuit means 8
The VM1 voltage at 0 is connected in series using the diode forward voltage VF so as to be 4 to 5 times the reference VM1 voltage converted from current to voltage by the current measuring current detection means 70. It becomes equal to the n-fold VM1 voltage.
In this way, the DC test current was prevented from flowing into the peak current bypass circuit means 80.

For example, the maximum V converted from current to voltage
If the M1 voltage is 1.5 V, it will be 6 V when quadrupled. For example, 10 diodes with a forward voltage of 0.6 V are connected in series. Since the peak current bypass circuit 81 of the diode forward connection and the peak current bypass circuit 82 of the reverse connection of the peak current bypass circuit means 80 are connected in parallel and are connected in reverse parallel, a total of 20 pieces are provided. used. DUT
In the functional test, since the maximum current flows as much as 800 mA, a diode having a large current capacity, for example, a current capacity of about 1.2 A is required. When 10v is applied to the DUT, 6v is required in the peak current bypass circuit means 80, so the supply voltage is 16v. 6 by peak current bypass circuit means 80
I also want to avoid using v. The power capacity of the output voltage control circuit 10 per channel is 800 mA × 16v =
12.8w was needed. Since the peak current bypass circuit means 80 takes n times the VM1 voltage, the supply voltage is (n-
1) It was necessary to set the voltage higher by double the VM1 voltage.
There has been a problem that the output voltage control circuit 10 requiring a high supply voltage and a large current capacity causes the voltage applied current measuring device to be upsized.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Four to five times the VM1 voltage converted from the current of the current detecting means for current measurement to the voltage.
It was necessary to double the forward voltage of the diode of the peak current bypass circuit means. It has a problem in that the diodes are connected in parallel by connecting a plurality of diodes in series, which means that the output voltage control circuit that supplies the voltage must supply that much higher voltage. I want to accurately control the peak current with the reference VM1 voltage of the peak current bypass circuit means to reduce the loss in the peak current bypass circuit and lower the supply voltage of the output voltage control circuit to reduce the overall current capacity. There was a problem. It is an object of the present invention to provide a voltage applied current measuring device in which the power capacity of an output voltage control circuit is reduced.

[0010]

In order to solve the above-mentioned object, in a voltage applied current measuring device, a peak current setting voltage equal to a reference VM1 voltage converted from a current of a current measuring current detecting means to a voltage is set. A peak current bypass circuit means for precise control is provided. Here, the description will focus on circuits near the peak current bypass circuit means 800. FIG. 2A shows peak current bypass circuit means, and FIG. 2B shows a plurality of diode characteristics in the peak current bypass circuit means. The peak current bypass circuit means 800, which is connected to the current measuring current detection means 70 and bypasses the peak current, is composed of the peak current bypass circuit 810 and the peak current bypass circuit 820 in reverse parallel connection.

The peak current bypass circuit 810 is a diode D.
1 and D2, D3, and D4 are connected in series, diodes D1 and D4 are connected to both ends of the current measuring current detection means 70, and a constant current source 15 for flowing a bias current from VDD between D2 and D4. Was set up. Peak current bypass circuit 820
Is a constant current for connecting the diodes D5, D6, D7 and D8 in series, and connecting the diodes D5 and D8 to both ends of the current measuring current detection means 70 so as to cause a bias current to flow from VCC between D5 and D7. Source 16 was provided. The sum V1 and D5, D6 of VF of the diodes D2, D3, D4 in the peak current bypass circuit 810 and the peak current bypass circuit 820,
The sum V2 of VF of D7 is V of the current detecting means 70 for current measurement.
Equal to the M1 voltage. The diodes D2, D3, D4 and the diodes D5, D6, D by the constant current sources 15 and 16
7 was always on. Peak current bypass circuit 810
The diode D1 and the diode D8 of the peak current bypass circuit 820 make a reverse connection with respect to the VM1 voltage, so that they are in an OFF state and the peak current bypass circuit means 80.
The zero currents I2 and I3 do not flow.

FIG. 2B shows a plurality of diode characteristics in the peak current bypass circuit means. The Y axis shows the currents I2 and I3 of the peak current bypass circuit means, and the X axis shows the VM1 voltage. The symbol in the figure is the characteristic of the invention circuit, is the positive side V
M1 voltage is the negative side VM1 voltage, is the positive side peak-time VM1 voltage, and is the negative side peak-time VM1 voltage. The absolute values of VM1 voltage and V1 and V2 are equal, which is equal to the sum of the forward voltage VF between diodes D2 and D4 and between D5 and D7.

When the sum of the reference VM1 voltage and the forward voltage VF of the diodes D1 and D8 is exceeded, the peak current bypass circuit 810 of the diode forward connection of the peak current bypass circuit means 800 and the reverse connection of the diode are connected. The diodes of the peak current bypass circuit 820 are turned on and the currents I2 and I3 are bypassed from the peak current bypass circuit means 800. Since the VM1 voltage of the peak current bypass circuit means 800, which has been conventionally increased from 4 times to 5 times, can be reduced to about 1/4, it is possible to provide a voltage applied current measuring device in which the output voltage of the output voltage control circuit 10 is lowered. became.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with examples.

[0015]

【Example】

(Embodiment 1) FIG. 1A shows a block diagram of a voltage applied current measuring apparatus according to an embodiment of the present invention, and FIG. 1B shows improvement of a diode clamp characteristic by a peak current bypass circuit means. In FIG. 1 of the present invention, the portions corresponding to those of FIG. The portion added by the present invention is a peak current bypass circuit means 8 connected to the portion of the current measuring current detecting means 70 converted from current to voltage.
00. An output voltage control circuit 10 that supplies a predetermined voltage to the DUT, a voltage feedback circuit 20 that operates to give a voltage equal to the voltage value given from the voltage setter 12 of the output voltage control circuit 10 to the terminals of the DUT, and a DUT. A current measuring current detecting means 70 for converting a test current into a voltage, a current measuring differential amplifier 90 for taking out the voltage converted from the current, and the taken-out voltage is converted into a digital signal by an AD converter 100. AD converter 100 for converting a peak current into a voltage, a current limiting current detecting resistor 40 for converting a peak current into a voltage, a current limiting differential amplifier 50 for extracting the voltage, and a peak current for setting a setting value of the limiting current. In the voltage applied current measuring device having the current limiting control circuit 60 which outputs the current limiting control current to the output voltage control circuit 10 when the voltage exceeds the current, the current measuring current detection is performed. Peak current side path circuit means for bypassing the peak current by connecting with the stage 70 800
Was provided.

In the peak current bypass circuit means 800 of the present invention, the peak current bypass circuit 810 and the peak current bypass circuit 820 are connected in parallel at both ends of the current measuring current detecting means 70. The peak current bypass circuit 810 includes diodes D1 and D
2, D3 and D4 are connected in series and connected to both ends of the current measuring current detecting means 70, and a constant current source 15 for supplying a constant current bias current from VDD is provided between D1 and D2.
The peak current bypass circuit 820 includes diodes D5, D6, D
7 and D8 are connected in series to form a current measuring current detecting means 70.
A constant current source 16 for supplying a constant current bias current from VCC is provided between D7 and D8. Both constant current sources 15 and 16 are the same constant current source. As a result, a constant bias voltage is applied between the diodes D2 to D7. As a result, the number of diodes used can be reduced as compared with the conventional circuit, and the supply voltage of the output voltage control circuit 10 can be lowered.

FIG. 1B shows the improvement of the clamp characteristic of the diode by the peak current bypass circuit means. The Y axis shows the currents I2 and I3 of the peak current bypass circuit means, and the X axis shows the VM1 voltage. Positive and negative side VM1 according to the present invention
The difference between the voltage and the VM1 voltage on the positive and negative sides according to the prior art is shown. The symbol in the figure is the characteristic of the invention circuit, is the positive side VM1
Voltage is the negative side VM1 voltage, is the positive side peak V
M1 voltage is the negative peak VM1 voltage, which is the characteristic of the conventional circuit according to the prior art, is the positive peak VM1 voltage, and is the negative peak VM1 voltage. In the prior art, a large number of diodes are connected in series in order to use the forward characteristic of the diode in a currentless region, but in the present invention, a bias voltage is applied between the diodes D2 to D7, so that a small number of diodes are connected in series. The connection gave the desired properties. As a result, the output voltage control circuit 10 was able to reduce the output voltage and supply power.

(Embodiment 2) FIG. 3A is a block diagram of a voltage applied current measuring apparatus according to an embodiment of the present invention, and FIG.
Shows the clamp characteristics of both transistors in the peak current bypass circuit means. In FIG. 3 of the present invention, parts corresponding to those of FIG. The portion added according to the present invention is a current measuring current detecting means 70.
It is the peak current bypass circuit means 900 connected to the part where the current is converted into the voltage. An output voltage control circuit 10 which supplies a predetermined voltage to the DUT, a voltage feedback circuit 20 which operates to give a voltage equal to the voltage value given from the voltage setter 12 of the output voltage control circuit 10 to the terminal of the DUT, and the DUT
Current detection means 70 for converting the current of the test of 1 to voltage, a current measurement differential amplifier 90 for extracting the voltage converted from the current, and the extracted voltage are converted into digital signals by the AD converter 100. AD converter 100 for converting the peak current into a voltage, a current limiting current detection resistor 40 for converting the peak current into a voltage, a current limiting differential amplifier 50 for extracting the voltage, and a set value for the peak current being the limiting current. In the voltage applied current measuring device having the current limiting control circuit 60 that outputs the current limiting control current to the output voltage control circuit 10 when the voltage exceeds the peak, the peak is bypassed by connecting to the current measuring current detecting means 70. A current bypass circuit means 900 is provided.

In the peak current bypass circuit means 900, the pnp type transistor 30 and the npn type transistor 31 are connected to both ends of the current measuring current detecting means 70 with the collector grounded, and a set voltage V which gives a reverse bias to each base.
Give 1, V2. In the peak current bypass circuit 910, the emitter and collector of the transistor 30 are connected to both ends of the current measuring current detecting means 70, the emitter is connected to the DUT side, and the collector is connected to the opposite side. A set voltage V1 is provided between the base and collector so that the voltage VBC1 can be controlled freely. Similarly, the peak current bypass circuit 920 has the emitter and collector of the transistor 31 connected to both ends of the current measuring current detection means 70, the emitter connected to the DUT side, and the collector connected to the opposite side. A set voltage V2 is provided between the base and collector so that the voltage VBC2 can be freely controlled.

FIG. 3B shows the clamp characteristics of both transistors in the peak current bypass circuit means. The Y axis shows the currents I2 and I3 of the peak current bypass circuit means, and the X axis shows the VM1 voltage. Collector-grounded transistor 30
And transistor 31 controls the base-collector voltages V1 and V2 to set the saturation region of the transistor equal to the reference VM1 voltage. Collector-grounded transistor 3
Between 0 and the saturation region of the transistor 31, the currents I2 and I3 of the peak current bypass circuit means 900 do not flow. The active regions of the peak current bypass circuit means 900 in which the currents I2 and I3 flow are collector-grounded transistors 30 and 3.
When the sum of the voltages V1 and V2 between the base and the collector and the voltage VBE between the base and the emitter of 1 is exceeded, the current is clamped. As a result, it is possible with two transistors as compared with the conventional technique that requires a large number of diodes.

(Embodiment 3) FIG. 4 shows a block diagram of a voltage applied current measuring apparatus according to an embodiment of the present invention. In FIG. 3 of the present invention, parts corresponding to those of FIG. The portion added by the present invention is peak current bypass circuit means 960 connected to the portion of the current measuring current detecting means 70 converted from current to voltage. D
An output voltage control circuit 10 for supplying a predetermined voltage to the UT,
The voltage setter 12 of the output voltage control circuit 10 is connected to the terminal of the DUT.
Voltage feedback circuit 20 that operates so as to give a voltage equal to the voltage value given from the current measurement current measuring means 70 for converting the current of the DUT test to the voltage, and current measurement for extracting the voltage converted from the current. Differential amplifier 90, an AD converter 100 for converting the extracted voltage into a digital signal by an AD converter, and a current limiting current detection resistor 40 for converting a peak current into a voltage, and the voltage thereof. In a voltage applied current measuring device having a current limiting differential amplifier 50 and a current limiting control circuit 60 which outputs a current limiting control current to the output voltage control circuit 10 when a peak current exceeds a set value of the limiting current, A peak current bypass circuit means 960 for connecting the current measuring current detection means 70 and bypassing the peak current is provided.

A P-channel type FE which is connected to both ends of the current measuring means 70 for current measurement and bypasses the peak current.
Peak current bypass circuit 97 consisting of drain ground of T33
A peak current bypass circuit means 960 constituted by a zero current and a peak current bypass circuit 980 formed by grounding the drain of the n-channel type FET 34 is provided. P-channel type FET3
Connect the anode side of diode D9, which blocks the reverse current from the drain to the source, to the drain inside
The cathode pole side of the diode D9 is connected to the source, and the diode D11 for blocking the current flowing through the diode D9 is provided. In actuality, the FET itself has a parasitic diode D9 and therefore need not be used. The peak current bypass circuit 970 is connected to the source of the P-channel type FET 33 and the cathode side of the diode D11, and the anode side of the diode D11 is connected to the current measuring current detection means 7.
The drain was connected to the side closer to the DUT, and the drain was connected to the opposite side with the current measuring current detection means 70 sandwiched therebetween. A set voltage V1 is provided so that the voltage VGS1 between the gate and drain can be controlled freely.

Inside the n-channel FET 34, a diode D1 for blocking a reverse current from the drain to the source.
Connect the cathode side of 0 to the drain to connect diode D
An anode pole side of 10 is provided to be connected to the source, and a diode D12 for blocking a current flowing through the diode D10 is provided. In actuality, the FET itself has a parasitic diode D10, so it need not be used. Peak current bypass circuit 9
80 is connected to the source of the n-channel type FET 34 and the anode pole side of the diode D12, and is connected to the diode D1.
The cathode side of 2 is the DU of the current detection means 70 for current measurement
The drain was connected to the side closer to T, and the drain was connected to the opposite side with the current measuring means for current measurement 70 sandwiched therebetween. Set voltage V2 that can freely control the voltage VGS2 between the gate and drain
Was provided.

The active region of the peak current bypass circuit means 960 includes the VM1 voltage and p, the gate-source voltages of the n-channel FETs 33 and 34 and the set voltages V1 and V2, and D11 and D.
The sum of the VF of 12 is compared, and when it becomes higher than the VM1 voltage, the currents I2 and I3 of the peak current bypass circuit means 960 flow. The saturation region is the gate-source voltage of the p- and n-channel FETs 33 and 34 and the set voltage V1, V2, and D11,
When the VM1 voltage is lower than the sum of the VF of D12 and the VM1 voltage, the p- and n-channel FETs 33 and 34 are cut off. Compared to the conventional technology that requires a large number of diodes, it is possible with two FETs and a small number of diodes.

In each of the above-mentioned embodiments, the description has been given of the example in which the current limiting resistance 40 for detecting the current, the differential amplifier 50 for limiting the current, and the control circuit 60 for limiting the current are provided. The same applies.

[0026]

The present invention is embodied in the form described above and has the following effects.

In the prior art, a clamp voltage of 4 to 5 times the reference VM1 voltage was required, but the present invention requires accurate control of the reference VM1 voltage of the peak current bypass circuit means as described above. Therefore, the output voltage control circuit can reduce the supply output voltage and supply power. It has become possible to reduce the size of the voltage applied current measuring device having multiple channels in one IC test system. Therefore, the present invention is very useful and has not only a technical effect but also an economic effect.

In the first embodiment, by providing a bias current to the diode, the number of devices used can be greatly reduced as compared with the prior art. This means that the supply voltage of the output voltage control circuit can be lowered and the voltage applied current measuring device can be reduced. Could be made smaller.

In the second embodiment, compared with the prior art which requires a large number of diodes, it is possible to use two transistors, so that the supply voltage of the output voltage control circuit can be lowered and the voltage applied current measuring device can be used. I was able to make it smaller.

In the third embodiment, compared with the prior art which requires a large number of diodes, it is possible to use two FETs and a small number of diodes, so that the supply voltage of the output voltage control circuit can be lowered and the voltage application. The current measuring device can be made compact.

[Brief description of the drawings]

FIG. 1A is a block diagram of a voltage applied current measuring device according to an embodiment of the present invention, and FIG. 1B shows improvement of a diode clamp characteristic by a peak current bypass circuit means.

FIG. 2A is a peak current bypass circuit means, and FIG.
Indicates a plurality of diode characteristics in the peak current bypass circuit means.

FIG. 3A is a block diagram of a voltage applied current measuring device according to an embodiment of the present invention, and FIG. 3B shows clamp characteristics of both transistors in a peak current bypass circuit means.

FIG. 4 is a block diagram of a voltage applied current measuring device according to an embodiment of the present invention.

5A shows a voltage applied current measuring device according to the prior art, and FIG. 5B shows a diode current characteristic in a peak current bypass circuit means.

[Explanation of symbols]

10 Output Voltage Control Circuit 11 Operational Amplifier 12 Voltage Setting Device 15 and 16 Constant Current Source 20 Voltage Feedback Circuit 21 Amplifier 40 Current Limiting Current Detecting Resistor 50 Current Limiting Differential Amplifier 60 Current Limiting Control Circuit 70 Current Measuring Current Detecting Means 71 Current measuring circuit for current measurement 72 Range switching means 80, 800, 900, 960 Peak current bypass circuit means 81, 810, 910, 970 Peak current bypass circuit 82, 820, 920, 980 Peak current bypass circuit 90 Current measurement differential amplifier circuit 100 AD converter 110 Current detection means D1, D2 Diodes D3, D4 Diodes D5, D6 Diodes D8, D9 Diodes D10, D11 Diodes D12 Diodes 30, 31 Transistors 33, 34 FET

Claims (3)

[Claims] 1. An output voltage control circuit (10) for supplying a predetermined voltage to a DUT, a voltage feedback circuit (20) for feeding back the voltage of a DUT terminal to the output voltage control circuit (10), and D.
A current measuring current detecting means (70) for converting the current of the UT test into a voltage, a current measuring differential amplifier (90) for extracting the voltage across the current measuring current detecting means (70),
In a voltage application current measuring device having an AD converter (100) for converting this into a digital signal, a peak current bypass circuit (810) connected to both ends of the current measuring current detecting means (70) to bypass the current. And a peak current bypass circuit (820) are connected in reverse parallel to each other to provide peak current bypass circuit means (800), and the peak current bypass circuit (810) is a diode (D1).
And at least one diode (D2) are connected in series to both ends of the current measuring current detecting means (70),
A bias constant current source (15) for biasing at least one diode (D2) in the forward direction is used, and the peak current bypass circuit (820) includes at least one diode (D7) and diode (D8) in series. Connect to both ends of the current measuring means (70) for current measurement,
A voltage applied current measuring device comprising a bias constant current source (16) for biasing at least one diode (D7) in a forward direction, and having the above configuration. 2. An output voltage control circuit (10) for supplying a predetermined voltage to the DUT, a voltage feedback circuit (20) for feeding back the voltage of the DUT terminal to the output voltage control circuit (10), and D.
A current measuring current detecting means (70) for converting the current of the UT test into a voltage, a current measuring differential amplifier (90) for extracting the voltage across the current measuring current detecting means (70),
In a voltage applied current measuring device having an AD converter (100) for converting this into a digital signal, a peak current bypass circuit (910) connected to both ends of the current measuring current detecting means (70) to bypass the current. And a peak current bypass circuit (920) are connected in reverse parallel to each other, and a peak current bypass circuit means (900) is provided. The peak current bypass circuit (910) includes a transistor (3
The emitter of 0) is connected to D of the current detecting means (70) for current measurement.
The peak current bypass circuit (920) is connected to the UT side, the collector is connected to the opposite side of the current measuring current detecting means (70), and a controllable setting voltage V1 is provided between the base and the collector. (3
The emitter of 1) is connected to D of the current detection means (70) for current measurement.
It is connected to the UT side, the collector is connected to the opposite side of the current measuring current detecting means (70), and a controllable set voltage V2 is provided between the base and the collector. Voltage applied current measuring device. 3. An output voltage control circuit (10) for supplying a predetermined voltage to the DUT, a voltage feedback circuit (20) for feeding back the voltage of the DUT terminal to the output voltage control circuit (10), and D.
A current measuring current detecting means (70) for converting the current of the UT test into a voltage, a current measuring differential amplifier (90) for extracting the voltage across the current measuring current detecting means (70),
In a voltage applied current measuring device having an AD converter (100) for converting this into a digital signal, a peak current bypass circuit (970) connected to both ends of the current measuring current detecting means (70) to bypass the current. And a peak current bypass circuit (980) are connected in reverse parallel to each other, and peak current bypass circuit means (960) is provided. The peak current bypass circuit (970) is a P-channel type FE.
The source of T (33) is connected to the cathode side of the diode (D11), the anode side of the diode (D11) is connected to the DUT side of the current measuring current detection means (70),
The drain is connected to the opposite side of the current measuring means for current measurement (70), and a set voltage V1 for freely controlling the voltage VGS1 between the gate and the drain is provided. The peak current bypass circuit (980) is an n-channel type FE.
The source of T (34) is connected to the anode side of the diode (D12), the cathode side of the diode (D12) is connected to the DUT side of the current measuring current detecting means (70), and the drain is current measuring current detecting. A voltage applied current measuring device having the above-mentioned configuration, which is connected to the opposite side of the means (70) and is provided with a set voltage V2 capable of freely controlling the voltage VGS2 between the gate and the drain.