JP2012129936A - Drive device, switch device and testing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FET drive circuit based on non-inverting amplification.SOLUTION: Provided is a drive device which comprises: a first reference voltage output section; a first voltage drop section disposed between a first terminal and a second terminal both situated between an input terminal and the first reference voltage output section to drop a voltage in accordance with a current flowing from the first terminal to the second terminal; a first current source connected between the first terminal and an output terminal; a second reference voltage output section for outputting a second reference voltage; a first switch section disposed between the output terminal and the second terminal and turned on or off in accordance with a difference between the second reference voltage and a voltage at the second terminal; and a compensation section for compensating for a change in the voltage dropped by the first voltage drop section while the first switch section is on and off.

Description

  The present invention relates to a drive device, a switch device, and a test device.

Conventionally, for the purpose of controlling on / off of a semiconductor switch such as a field effect transistor (FET), a driving signal supplied to the gate of the switch is formed by a driving device using a semiconductor circuit (for example, a patent) Reference 1).
Patent Document 1 JP 2003-318722 A

  However, since such a drive device inverts and amplifies the input voltage using an inverter circuit or the like, it is difficult to realize a drive device that non-inverts and amplifies an input signal, for example. In addition, it has been difficult to form such a circuit with a semiconductor switch circuit such as an FET in consideration of variations in manufacturing characteristics of semiconductor elements.

  In order to solve the above-described problem, according to a first aspect of the present invention, there is provided a driving device that outputs an output voltage corresponding to an input voltage to be input to an input terminal from the output terminal, and outputs a first reference voltage. 1 reference voltage output unit, provided between the first terminal and the second terminal located between the input terminal and the first reference voltage output unit, the voltage according to the current flowing from the first terminal to the second terminal Between the first voltage drop unit for dropping, the first current source connected between the first terminal and the output terminal, the second reference voltage output unit for outputting the second reference voltage, and the output terminal and the second terminal The first switch part that is turned on or off according to the difference between the second reference voltage and the voltage of the second terminal, and the first voltage drop part in the state where the first switch part is on and off lowers A compensation unit for compensating for a change in voltage. To provide a dynamic system.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

The structure of the drive device 100 which concerns on this embodiment is shown. Provided in the driving device 100 according to this embodiment, each of the gates of the FET - shows an example of characteristics of drain current I _D with respect to the voltage V _GS between source. The structure of the switch apparatus 10 which concerns on this embodiment is shown. 1 shows a configuration of a test apparatus 200 according to the present embodiment, together with a device under test 300.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows a configuration of a driving apparatus 100 according to the present embodiment. The driving device 100 outputs an output voltage corresponding to the input voltage input to the input terminal from the output terminal. As an example, the driving device 100 outputs a -19V on drive signal to a + 3V input, and outputs a -29V off drive signal to a 0V input.

  The driving apparatus 100 includes a first voltage drop unit 110, a first current source 120, a first switch unit 130, a compensation unit 140, a first reference voltage output unit 150, a second reference voltage output unit 160, A third current source 170, a first voltage adjustment unit 180, and a second voltage adjustment unit 190 are provided. In addition, the driving apparatus 100 has a first terminal and a second terminal between the input terminal and the first reference voltage output unit 150. In addition, the driving device 100 positions the third terminal and the fourth terminal between the input terminal and the first terminal.

  The first voltage drop unit 110 is provided between the first terminal and the second terminal, and drops the voltage according to the current flowing from the first terminal to the second terminal. The first voltage drop unit 110 may be a resistor. The first voltage drop unit 110 shifts the voltage value calculated by multiplying the resistance value of the resistor and the magnitude of the current flowing through the first voltage drop unit 110 from the voltage at the first terminal. As an example, the first voltage drop unit 110 is a 70 kΩ resistor.

  The first current source 120 is connected between the first terminal and the output terminal. The first current source 120 allows a constant current to flow from one end connected to the first terminal to the other end connected to the output terminal and the first switch unit 130. The first current source 120 includes an FET and a resistor, and may function as a constant current source. For example, the first current source 120 is a constant current circuit in which one end of a resistor is connected to the source of the FET, the other end is connected to the gate of the FET, and a current of 20 μA flows from the drain of the FET to the other end of the resistor. .

  The first switch unit 130 is provided between the output terminal and the second terminal, and is turned on or off according to the difference between the second reference voltage output unit 160 and the voltage of the second terminal. The first switch unit 130 may be an FET having a gate connected to the second reference voltage output source, a drain connected to the output terminal and the first current source 120, and a source connected to the second terminal. Here, the first switch unit 130 may be a switch that is turned off when + 3V of the on-voltage is input as the input voltage and turned on when 0V of the off-voltage is input as the input voltage.

  The compensation unit 140 compensates for a change in voltage that the first voltage drop unit 110 drops when the first switch unit 130 is on and off. The compensation unit 140 is provided between the third terminal and the fourth terminal. The compensation unit 140 includes a second voltage drop unit 142, a second current source 144, and a second switch unit 146.

  The second voltage drop unit 142 drops the voltage according to the current flowing from the third terminal to the fourth terminal. The second voltage drop unit 142 may be a resistor. The second voltage drop unit 142 shifts the voltage value calculated by multiplying the resistance value of the resistor by the magnitude of the current flowing through the second voltage drop unit 142 from the voltage at the third terminal. As an example, the second voltage drop unit 142 is a 70 kΩ resistor.

  The second current source 144 has one end connected to the third terminal. The second current source 144 allows a constant current to flow from one end connected to the third terminal to the other end connected to the second switch unit 146. Similar to the first current source 120, the second current source 144 may include an FET and a resistor, and may function as a constant current source. For example, the second current source 144 is a constant current circuit in which one end of the resistor is connected to the source of the FET, the other end is connected to the gate of the FET, and a current of 20 μA flows from the drain of the FET to the other end of the resistor. .

  The second switch unit 146 is provided between the other end of the second current source 144 and the fourth terminal. The second switch unit 146 is turned off when the first switch unit 130 is turned on, and is turned on when the first switch unit 130 is turned off. It becomes. The second switch unit 146 is connected to the output terminal and is turned on or off according to the output voltage. Similarly to the first switch unit 130, the second switch unit 146 has a gate connected to the second reference voltage output source, a drain connected to the output terminal and the first current source 120, and a source connected to the second terminal. FET may be used.

  The first switch unit 130 and the second switch unit 146 may be N-channel depletion type, and may be normally-on type FETs that are turned on when the gate-source voltage is 0V. The first switch unit 130 and the second switch unit 146 may be FETs formed of a compound semiconductor, for example, a GaN-based HEMT. Further, the first switch unit 130 and the second switch unit 146 may have a MIS (Metal-Insulator-Semiconductor) structure.

  The first reference voltage output unit 150 outputs a first reference voltage. The second reference voltage output unit 160 outputs a second reference voltage. Here, the second reference voltage may be higher than the first reference voltage. As an example, the first reference voltage is −48V and the second reference voltage is −35.5V.

  The third current source 170 defines a current flowing between the second terminal and the first reference voltage output unit 150. For example, the third current source 170 is a constant current circuit in which one end of the resistor is connected to the source of the FET, the other end is connected to the gate of the FET, and a current of 100 μA flows from the drain of the FET to the other end of the resistor. . Similar to the first current source 120, the third current source 170 may include an FET and a resistor and function as a constant current source. The first current source 120, the second current source 144, and the third current source 170 may each have an N-channel depletion type and a gate-structure normally-on type FET having a Schottky structure.

  The first voltage adjustment unit 180 is provided between the input terminal and the third terminal, and reduces the voltage according to the current flowing from the input terminal to the third terminal. The first voltage adjustment unit 180 may be a resistor. As an example, the first voltage adjustment unit 180 is a 112 kΩ resistor.

  The second voltage adjusting unit 190 is provided between the fourth terminal and the first terminal, and reduces the voltage according to the current flowing from the fourth terminal to the first terminal. The second voltage adjustment unit 190 may be a resistor. As an example, the second voltage adjustment unit 190 is a 52 kΩ resistor.

FIG. 2 shows an example of the characteristics of the drain current _ID with respect to the gate-source voltage V _GS of each of the plurality of FETs provided in the driving apparatus 100 according to the present embodiment. As an example, all FETs included in the driving apparatus 100 have characteristics as shown in FIG.

  The characteristic in the figure has a normally-on characteristic in which a drain current flows even when the gate-source voltage is zero, and shows a characteristic of an N-channel depletion type FET. In this example, the first switch unit 130 and the second switch unit 146 are completely turned on when the gate-source voltage is -6 V or more, and are completely turned off when the gate-source voltage is -9 V or less. Become. Here, when the gate-source voltage is in the range from -6V to -8V, the FET is not completely turned on or completely turned off (half-on state), and several μm between the drain-source. A current of up to several hundred μA is applied.

  In this example, the first current source 120, the second current source 144, and the third current source 170 are completely turned on when the gate-source voltage is −1.8 V or more, and the gate-source voltage is − Each has a Schottky FET which is completely turned off when the voltage is 4.8 V or less. Here, when the gate-source voltage is in the range of −1.8 V to −3.8 V, the FET is not completely turned on or completely turned off (half-on state), and the drain-source A current of several μ to several hundred μA is passed between them.

  For example, when the gate-source voltage is -3.6V and the FET is in a half-on state and a current of 20 μA flows, the first current source 120 and the second current source 144 are 180 kΩ obtained by dividing 3.6 V by 20 μA. Each has a resistance. Thereby, the first current source 120 and the second current source 144 each function as a constant current source for flowing a current of 20 μA.

  Similarly, when the gate-source voltage is -3.4V and the FET is in a half-on state and a current of 100 μA flows, the third current source 170 has a resistance of 34 kΩ obtained by dividing 3.4 V by 100 μA. Thus, the third current source 170 functions as a constant current source for supplying a current of 100 μA.

  In the driving apparatus 100 of this example, the voltage of + 3V / 0V, which is an input on / off signal from the input terminal, is applied to the first voltage drop unit 110, the second voltage drop unit 142, the first voltage adjustment unit 180, and the second voltage. Each voltage is shifted by the adjustment unit 190.

  For example, when the second current source 144 and the second switch unit 146 of the driving apparatus 100 are not provided, a current of 100 μA flows from the input terminal to the first terminal, so that the first voltage adjustment unit 180 is set to 11.2V, the second voltage The drop unit 142 shifts the voltage by 7V, and the second voltage adjustment unit 190 shifts the voltage by 5.2V. Therefore, for an input signal of + 3V / 0V, the first terminal is −20.4V / −23.4V.

  Here, when the first switch unit 130 is in an OFF state, no current flows through the first current source 120 and a current of 100 μA flows through the first voltage drop unit 110. Therefore, the first voltage drop unit 110 has a voltage of 7V. Shift voltage. When the input ON signal + 3V is input, the driving apparatus 100 turns off the first switch unit 130 and outputs the voltage of the first terminal from the output terminal. That is, the driving device 100 outputs −20.4V from the output terminal and sets the second terminal to −27.4V in response to the input ON signal of + 3V.

  On the other hand, when the first switch unit 130 is turned on, a current of 20 μA flows through the first current source 120, so that a current of 80 μA flows through the first voltage drop unit 110, and the first voltage drop unit 110 is 5.6V. Shift the voltage. When 0V of the input off signal is input, the driving device 100 turns on the first switch unit 130 and outputs the voltage of the second terminal from the output terminal. That is, the driving device 100 sets the output voltage from the output terminal and the second terminal to −29 V in response to the 0 V input off signal.

  As described above, the driving device 100 can function as non-inverting amplification by outputting a voltage of −20.4 V / −29 V with respect to +3 V / 0 V of the input on / off signal. On the other hand, the driving device 100 sets the voltage of the second terminal to −27.4V / −29V with respect to + 3V / 0V of the input on / off signal. Since the difference between the voltage at the second terminal and the second reference voltage is the gate-source voltage of the first switch unit 130, the drive device has a voltage difference of 3V on / off signal at the input terminal. 100 reduces the voltage difference of the on / off signal of the gate-source voltage to 1.6V.

  The driving apparatus 100 may set the second reference voltage to −36.9 V and the gate-source voltage to −9.5 V so that the first switch unit 130 is completely turned off. In this case, since the voltage difference between the on / off signals is 1.6 V, the driving apparatus 100 sets the on-voltage of the gate-source voltage to −7.9 V and turns the first switch unit 130 into a half-on state. However, the characteristics of the drain current with respect to the gate-source voltage shown in FIG. 2 fluctuate due to variations in the manufacture of the FET, etc., so that the first switch unit 130 is changed only by, for example, about 0.2 V in the horizontal axis direction. Switching operation becomes unstable.

  Therefore, the driving apparatus 100 according to the present embodiment includes the compensation unit 140 and the first voltage when the first switch unit 130 is on and off so that the on / off voltage difference of the first switch unit 130 does not decrease. A change in voltage dropped by the drop unit 110 is compensated. That is, the compensation unit 140 makes the sum of the voltage dropped by the first voltage drop unit 110 and the voltage dropped by the second voltage drop unit 142 constant when the first switch unit 130 is on and off. The current flowing through the second voltage drop unit 142 is switched according to the state of the first switch unit 130.

  For example, the compensation unit 140 includes a second voltage drop unit 142, a second current source 144, and a second switch unit that are substantially the same as the circuit having the first voltage drop unit 110, the first current source 120, and the first switch unit 130. 146. Here, the first current source 120 and the second current source 144 may have the same characteristics. As an example, the compensation unit 140 sets the current flowing through the second voltage drop unit 142 to 100 μA when the current flowing through the first voltage drop unit 110 is 80 μA, and sets the current flowing through the first voltage drop unit 110 as 100 μA. 2 The current flowing through the voltage drop unit 142 is set to 80 μA.

  More specifically, when the second switch unit 146 is off, no current flows through the second current source 144 and 100 μA flows through the second voltage drop unit 142. The voltage shift is 11.2V, the second voltage drop unit 142 is 7V, and the second voltage adjustment unit 190 is 5.2V. Here, when the second switch unit 146 is off, the first switch unit 130 is on and the driving device 100 is off. That is, the driving device 100 sets the third terminal to −11.2 V, the fourth terminal to −18.2 V, and the first terminal to −23.4 V with respect to the 0 V off-state input signal.

  Here, when the first switch unit 130 is on, a current of 20 μA flows through the first current source 120, so that a current of 80 μA flows through the first voltage drop unit 110. Shift the voltage of 6V. Therefore, the driving apparatus 100 sets the output terminal and the second terminal to −29V with respect to the 0V input off signal.

  On the other hand, when the second switch unit 146 is on, a current of 20 μA flows through the second current source 144 and a current of 80 μA flows through the second voltage drop unit 142. The voltage shift is 2V, the second voltage drop unit 142 is 5.6V, and the second voltage adjustment unit 190 is 5.2V. Here, when the 2nd switch part 146 is ON, the 1st switch part 130 is OFF and the drive device 100 is ON. That is, the driving device 100 sets the third terminal to −8.2V, the fourth terminal to −13.8V, and the first terminal to −19V with respect to the input signal of + 3V of the ON voltage.

  Here, when the first switch unit 130 is in an OFF state, no current flows through the first current source 120 and a current of 100 μA flows through the first voltage drop unit 110. Therefore, the first voltage drop unit 110 has a voltage of 7V. Shift voltage. Therefore, the driving device 100 sets the output voltage from the first terminal and the output terminal to −19V and the second terminal to −26V with respect to the input ON signal of + 3V.

  As described above, the driving device 100 can function as non-inverting amplification by outputting a voltage of −19 V / −29 V with respect to +3 V / 0 V of the input on / off signal. Further, the driving device 100 outputs a voltage of −26V / −29V as the voltage of the second terminal with respect to + 3V / 0V of the input on / off signal. In other words, the driving device 100 can directly apply the 3 V on / off voltage difference given at the input terminal as the on / off voltage difference between the gate and source voltages of the first switch unit 130.

  Here, the driving device 100 sets the on / off voltage of the gate-source voltage of the first switch unit 130 to −6.5V / −9.5V by setting the second reference voltage to −35.5V. Can do. Accordingly, the first switch unit 130 is completely turned off by setting the voltage of −9.5 V to the gate-source voltage, and is turned on by setting the voltage of −6.5 V to the gate-source voltage. It becomes a state.

  Accordingly, the first switch unit 130 is turned off when the driving device 100 is in the on state, and is turned on when the driving device 100 is in the off state. In addition, the second switch unit 146 is turned on because the gate-source voltage is −5.2 V, which is a voltage difference between the fourth terminal and the first terminal, when the first switch unit 130 is off. Further, the second switch unit 146 is turned off because the gate-source voltage is set to −10.8 V which is a voltage difference between the fourth terminal and the second terminal when the first switch unit 130 is on.

  As described above, when the driving device 100 sets the gate-source voltage on / off voltage difference to 3 V, the drain current characteristic with respect to the gate-source voltage varies from −0.5 V in the horizontal axis direction due to manufacturing variation. Even if the voltage fluctuates by about +0.5 V, the first switch unit 130 can perform a stable switching operation.

  FIG. 3 shows a configuration of the switch device 10 according to the present embodiment. The switch device 10 electrically connects or disconnects between the first switch terminal 12 and the second switch terminal 14. The switch device 10 conducts or disconnects between the first switch terminal 12 and the second switch terminal 14 in accordance with the voltage of the control signal input from the outside. The switch device 10 includes a main FET 20, an ON FET 22, an OFF FET 24, an ON side input resistor 26, an OFF side input resistor 28, a control unit 30, and a voltage detection unit 32.

  The main FET 20 functions as a main switch provided between the first switch terminal 12 and the second switch terminal 14. The main FET 20 transmits the signal received from the first switch terminal 12 to the second switch terminal 14. The main FET 20 has a source connected to the first switch terminal 12 and a drain connected to the second switch terminal 14. In the present embodiment, the main FET 20 is an N-channel depletion type, and is a normally-on type field effect transistor that is turned on when the gate-source voltage is 0V.

  The on FET 22 functions as an on switch electrically connected between the first switch terminal 12 and the gate of the main FET 20. The ON FET 22 has a source connected to the source of the main FET 20 and a drain connected to the gate of the main FET 20.

  The off FET 24 functions as an off switch connected between the gate of the main FET 20 and an off voltage for turning off the main FET 20. The off FET 24 has a source connected to the off voltage terminal 40 of the control unit 30 and a drain connected to the gate of the main FET 20.

  One end of the on-side input resistor 26 is connected to the on-side terminal 42 of the control unit 30, and the other end is connected to the gate of the on-use FET 22. One end of the off-side input resistor 28 is connected to the off-side terminal 44 of the control unit 30, and the other end is connected to the gate of the off-use FET 24.

  The voltage detector 32 detects whether or not the voltage of the second switch terminal 14 is within the reference range. In the present embodiment, the voltage detector 32 detects whether or not the voltage of the second switch terminal 14 has become less than the reference voltage.

  The voltage detection unit 32 includes a detection FET 34 provided between the second switch terminal 14 and the detection terminal 52 of the control unit 30. The detection FET 34 disconnects between the second switch terminal 14 and the detection terminal 52 of the control unit 30 when the voltage of the second switch terminal 14 is within the reference range, and the voltage of the second switch terminal 14 is out of the reference range. In this case, it functions as a detection switch that conducts between the second switch terminal 14 and the detection terminal 52 of the control unit 30.

  In the present embodiment, the detection FET 34 is an N-channel depletion type field effect transistor. The detection FET 34 has a source connected to the second switch terminal 14, a drain connected to the detection terminal 52 of the control unit 30, and a gate connected to the gate voltage terminal 54 of the control unit 30. The detection FET 34 is turned off when the voltage of the second switch terminal 14 is equal to or higher than a predetermined reference voltage (during normal operation). The detection FET 34 is turned on when the voltage at the second switch terminal 14 is lower than a predetermined reference voltage (during abnormal operation).

  The control unit 30 controls the main FET 20 to be turned on or off according to the voltage of the control signal input to the control terminal 50. When the main FET 20 is turned on, the control unit 30 turns on the on FET 22 and turns off the off FET 24. Further, when the main FET 20 is turned off, the control unit 30 turns off the on FET 22 and turns on the off FET 24.

  In the present embodiment, the control unit 30 receives a low-side (off) voltage when the main FET 20 is turned on as a control signal input to the control terminal 50 and a high side when the main FET 20 is turned off. (ON) voltage is received. The control unit 30 includes a driving device 100 and an inversion driving device 310.

  The driving device 100 and the reverse driving device 310 receive a control signal input to the control terminal 50. When receiving the off control signal, the driving device 100 outputs a drive voltage obtained by non-inverting amplification of the off control signal from the off side terminal 44 as an off side control voltage. Further, when the driving device 100 receives the ON control signal, the driving device 100 outputs the driving voltage obtained by non-inverting amplification of the ON control signal as the OFF side control voltage from the OFF side terminal 44.

  Accordingly, the switch device 10 can non-invert-amplify the control signal according to the on / off control signal and supply it as the gate drive signal of the off FET 24 by the driving device 100 formed of FET. In addition, the switch device 10 can amplify the control signal having a 3V amplitude three times or more by the drive device 100 formed of an FET, and can stably supply the control signal to the off FET 24 as a gate drive signal.

  When receiving the off control signal, the inverting drive device 310 outputs a drive voltage obtained by inverting and amplifying the off control signal as the on-side control voltage. When receiving the ON control signal, the inversion driving device 310 outputs a driving voltage obtained by inverting and amplifying the ON control signal as the ON side control voltage. The inverting drive device 310 may have an inverter circuit.

  Thus, the control unit 30 outputs the on-side control voltage from the on-side terminal 42. The ON-side control voltage output from the ON-side terminal 42 is applied to the gate of the ON FET 22 via the ON-side input resistor 26. The control unit 30 controls the on / off state of the on FET 22 by changing the level of the on-side control voltage in accordance with the voltage of the control signal input from the control terminal 50.

  Further, the control unit 30 outputs an off-side control voltage from the off-side terminal 44. The off-side control voltage output from the off-side terminal 44 is applied to the gate of the off FET 24 via the off-side input resistor 28. The control unit 30 controls the on / off of the off FET 24 by changing the level of the off-side control voltage according to the voltage of the control signal input from the control terminal 50.

  When the on FET 22 is turned on and the off FET 24 is turned off, the gate-source voltage of the main FET 20 becomes 0V. The main FET 20 is a normally-on type that is turned on when the gate-source voltage is 0V. Therefore, the control unit 30 can turn on the main FET 20 by turning on the FET 22 for turning on and turning off the FET 24 for turning off.

  Further, the control unit 30 outputs an off voltage that turns off the main FET 20 from the off voltage terminal 40. That is, the control unit 30 sets the gate voltage at which the main FET 20 can be completely turned off when the voltage in a predetermined range is applied to the first switch terminal 12 from the off voltage terminal 40 as an off voltage. Output. Thus, when the on FET 22 is turned off and the off FET 24 is turned on, a potential difference at which the main FET 20 is completely turned off is applied to the gate-source voltage of the main FET 20. Therefore, the control unit 30 can turn off the main FET 20 by turning off the on FET 22 and turning on the off FET 24.

  The control unit 30 turns off the detection FET 34 when the voltage of the second switch terminal 14 is equal to or higher than the reference voltage (during normal operation), and turns off when the voltage of the second switch terminal 14 is lower than the reference voltage (during abnormal operation). The reference gate voltage that is turned on is output from the gate voltage terminal 54. Thus, the control unit 30 disconnects the second switch terminal 14 and the detection terminal 52 of the control unit 30 during normal operation, and detects the second switch terminal 14 and the control unit 30 during abnormal operation. The terminals 52 can be made conductive.

  Then, when the voltage at the second switch terminal 14 is out of the reference range (for example, when the voltage at the second switch terminal 14 is less than the reference voltage), the control unit 30 forcibly turns off the main FET 20. . That is, the control unit 30 relates to the voltage of the control signal when the detection FET 34 of the voltage detection unit 32 is on (that is, when the second switch terminal 14 and the detection terminal 52 of the control unit 30 are conducted). First, the on FET 22 is forcibly turned off and the off FET 24 is turned on, and the main FET 20 is turned off.

  In such a switch device 10, the main FET 20 is turned on by conducting between the gate and the source of the main FET 20 by the ON FET 22, so that the gate of the main FET 20 can be in a floating state. Thereby, according to the switch apparatus 10, it is possible to improve the insulating property of the gate of the main FET 20 and improve the passage characteristic of the signal transmitted between the source and the drain.

  Further, such a switch device 10 detects the occurrence of an abnormal voltage at the second switch terminal 14 by the detection FET 34 without detecting it by an AD converter or the like. Therefore, the switch device 10 can forcibly turn off the main FET 20 without using a processor when an abnormal voltage is generated at the second switch terminal 14. Thereby, according to the switch apparatus 10, a circuit scale can be made small.

  FIG. 4 shows the configuration of the test apparatus 200 according to this embodiment together with the device under test 300. The test apparatus 200 tests the device under test 300.

  The test apparatus 200 includes a test signal generation unit 210, a driver 220, a comparator 230, a determination unit 240, a switch device 10, and a switch control unit 250. The test signal generator 210 generates a test signal for testing the device under test 300.

  The driver 220 supplies the test signal generated from the test signal generator 210 to the device under test 300. The comparator 230 acquires the logical value of the response signal output from the device under test 300 in response to the supply of the test signal. The determination unit 240 compares the logical value acquired by the comparator 230 with the expected value to determine pass / fail of the device under test 300.

  The switch device 10 is provided between the test signal generator 210 and the device under test 300. In this example, the switch device 10 is provided between the driver 220 and the device under test 300. The switch device 10 conducts or disconnects between the test signal generator 210 and the device under test 300 according to the voltage of the control signal supplied from the switch controller 250. The switch control unit 250 puts the switch device 10 into a conductive state during a test by the test signal generation unit 210 and puts the switch device 10 into a disconnected state other than during the test by the test signal generation unit 210.

  As a result, the test apparatus 200 is composed of a FET that is small, has a long life, and is highly reliable, and can perform a test using the switch apparatus 10 that is driven by the non-inverting amplification driving apparatus 100.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

10 switch device, 12 first switch terminal, 14 second switch terminal, 20 main FET, 22 ON FET, 24 OFF FET, 26 ON side input resistance, 28 OFF side input resistance, 30 control unit, 32 voltage detection unit , 34 detection FET, 40 off voltage terminal, 42 on side terminal, 44 off side terminal, 50 control terminal, 52 detection terminal, 54 gate voltage terminal, 100 driving device, 110 first voltage drop unit, 120 first current source , 130 1st switch part, 140 compensation part, 142 2nd voltage drop part, 144 2nd current source, 146 2nd switch part, 150 1st reference voltage output part, 160 2nd reference voltage output part, 170 3rd current Source, 180 first voltage adjustment unit, 190 second voltage adjustment unit, 200 test apparatus, 210 test signal generation unit, 220 driver, 30 comparators, 240 determination unit, 250 switch controller, 300 a device under test, 310 inversion driving device

Claims (11)

A drive device that outputs from the output terminal an output voltage corresponding to the input voltage to be input to the input terminal,
A first reference voltage output unit that outputs a first reference voltage;
A first terminal provided between the first terminal and the second terminal located between the input terminal and the first reference voltage output unit, wherein the voltage drops according to the current flowing from the first terminal to the second terminal; 1 voltage drop part,
A first current source connected between the first terminal and the output terminal;
A second reference voltage output unit for outputting a second reference voltage;
A first switch unit provided between the output terminal and the second terminal and turned on or off according to a difference between the second reference voltage output unit and the voltage of the second terminal;
A compensation unit that compensates for a change in voltage that the first voltage drop unit drops when the first switch unit is on and off;
A drive device comprising: The compensation unit
A second voltage drop provided between a third terminal and a fourth terminal located between the input terminal and the first terminal, wherein the voltage drops according to a current flowing from the third terminal to the fourth terminal; And
A second current source having one end connected to the third terminal;
A second switch unit that is provided between the other end of the second current source and the fourth terminal, and is turned off when the first switch unit is on and turned on when the first switch unit is off. When,
The drive device according to claim 1, comprising:   The drive device according to claim 2, wherein the second switch unit is connected to the output terminal and is turned on or off according to an output voltage.   The driving device according to claim 2, wherein the first current source and the second current source have the same characteristics.   5. The drive device according to claim 2, wherein the first voltage drop unit and the second voltage drop unit are resistors. 6.   6. The driving device according to claim 3, wherein the first switch unit and the second switch unit are transistors having a MIS structure. 7.   The driving apparatus according to claim 6, wherein the first switch unit and the second switch unit are GaN-based HEMT switches.   8. The drive device according to claim 1, further comprising a third current source that regulates a current flowing between the second terminal and the first reference voltage output unit. 9. A switch device for electrically connecting or disconnecting between a first switch terminal and a second switch terminal,
The drive device according to any one of claims 1 to 8, wherein a drive voltage corresponding to an input voltage to the input terminal is output from the output terminal;
A main switch that is turned on or off according to the driving voltage;
A switch device comprising: The switch device is
An ON switch electrically connected between the first switch terminal and the gate of the main switch;
An off switch connected between the gate of the main switch and an off voltage for turning off the main switch;
An on drive circuit for supplying a drive voltage to the on switch;
Further comprising
When the main switch is turned on, the on drive circuit turns on the on switch, and when the drive device turns off the off switch and turns off the main switch, the on drive circuit The switch device according to claim 9, wherein the on switch is turned off, and the driving device turns off the off switch. A test apparatus for testing a device under test,
A test signal generator for generating a test signal for testing the device under test;
The switch device according to claim 9 or 10, which is provided between the test signal generator and the device under test, and conducts or disconnects between the test signal generator and the device under test.
A test apparatus comprising:

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