CN217404462U - Test circuit - Google Patents
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- CN217404462U CN217404462U CN202122721584.XU CN202122721584U CN217404462U CN 217404462 U CN217404462 U CN 217404462U CN 202122721584 U CN202122721584 U CN 202122721584U CN 217404462 U CN217404462 U CN 217404462U
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Abstract
The application provides a test circuit, which comprises a switch module, a measuring device and a floating control circuit, wherein the switch module is used for controlling a device to be tested to be connected into the corresponding test circuit according to an action signal so as to enable the test circuit to reach a corresponding working state; the measuring device is connected with the switch module and is used for measuring the leakage current of the device to be measured; and the floating control circuit is connected with the switch module and the measuring device and used for providing an action signal for the switch module according to the action of the received test trigger signal so as to control the action of the switch module. Among the above-mentioned test circuit, through setting up the control circuit that floats, carry out independent control to the switch coil, separate with normal test circuit, reduction switch that can furthest is to test circuit's influence, and in addition, test circuit can realize the switching of the test circuit of different parameters in a flexible way through the break-make of switch, improves the efficiency of test, satisfies the large-scale industrial production demand.
Description
Technical Field
The present application relates to the field of circuit testing technologies, and in particular, to a test circuit.
Background
In integrated circuit testing, particularly testing of semiconductor discrete devices (such as MOSFETs, triodes, IGBTs, etc.), it is often necessary to perform a leakage current Test on a Device Under Test (hereinafter DUT). In the actual test process, other parameter tests except for the leakage current can be simultaneously carried out on the same clamp, so that a switching circuit needs to be added to carry out switching and testing on a plurality of test circuits during the design of the test circuit.
Generally, a method for switching a test circuit is to connect switches in series, and the test circuit is switched by turning on/off the switches, but leakage current caused by leakage resistance of the switches cannot be ignored in a nano-ampere-level or even pico-ampere-level leakage current test of semiconductor discrete devices due to unavoidable leakage resistance between coils and contacts of the switches. In large-scale industrial production, in order to improve the test efficiency, test equipment (including test power supply, test instrument, etc.) often is complete equipment, and test is carried out in a mode of outwards leading out a test probe, so that in a semiconductor micro-current test circuit with a switch, the test equipment can inevitably introduce switch leakage current interference, the accuracy of semiconductor test is seriously influenced, the switch leakage current is eliminated, and the problem to be solved urgently in the integrated circuit test is formed.
SUMMERY OF THE UTILITY MODEL
In view of the above, it is desirable to provide a test circuit for solving the problem of inaccurate leakage current test of a Device Under Test (DUT) caused by switch leakage current in a conventional semiconductor test circuit including a switch switching circuit.
The application provides a test circuit, which comprises a switch module, a measuring device and a floating control circuit, wherein the switch module is used for controlling a device to be tested to be connected into the corresponding test circuit according to an action signal so as to enable the test circuit to reach a corresponding working state; the measuring device is connected with the switch modules and is used for measuring the leakage current of the device to be measured; and the floating control circuit is connected with the switch module and the measuring device and used for providing the action signal for the switch module according to the action of the received test trigger signal so as to control the action of the switch module.
In the test circuit provided in the above embodiment, the floating control circuit is arranged to independently control the switch coil, and the switch coil is separated from the normal test circuit, so that the influence of the switch on the test circuit can be reduced to the maximum extent, and an isolation power supply with a voltage value far smaller than that of the test power supply is arranged in the floating control circuit, so that a working power supply is provided for the switch coil, the voltages at two ends of the leakage resistance of the switch can be greatly reduced, and then the influence of the leakage current of the switch on the leakage current of a device to be tested can be greatly reduced.
In one embodiment, the action signals include a leakage current test action signal and other test action signals, and the switch module includes:
a first switch configured to: the first contact is connected with a first power supply through the measuring device, the second contact is connected with the device to be tested, and the first coil port and the second coil port are both connected with the floating control circuit;
the first switch is further configured to: the device to be tested is controlled to be connected to a leakage current test circuit by closing according to the leakage current test action signal, or the device to be tested is controlled to be connected to the leakage current test circuit by opening according to the other test action signals;
a second switch configured to: the first contact is connected with the second contact of the first switch, the second contact is connected with other test circuits, and the first coil port and the second coil port are both connected with the floating control circuit;
the second switch is further configured to: according to the leakage current test action signal, the connection between the device to be tested and the other test circuits is cut off, or according to the other test action signals, the connection is closed, so that the device to be tested is controlled to be connected to the test loops of the other test circuits;
a third switch configured to: the first contact is connected with both the first power supply and the floating control circuit, the second contact is connected with the second contact of the second switch, the first coil port is connected with the second power supply, and the second coil port is connected with the floating control circuit;
the third switch is further configured to: and closing according to the leakage current test action signal to enable the first contact of the second switch and the second contact of the second switch to be in short circuit through the measuring device, or opening according to the other test action signals.
In one embodiment, the operating state comprises a leakage current test operating state, and the switching module is configured to:
the first switch is closed, the second switch is opened, the third switch is closed, and the integrated circuit test circuit enters a leakage current test working state.
In one embodiment, the operating state includes other test operating states, the switch module is configured to:
the first switch is turned off, the second switch is turned on, the third switch is turned off, and the integrated circuit test circuit enters other test working states.
In one embodiment, the floating control circuit includes:
the isolation power supply is connected with the first power supply, the second power supply, the first switch, the second switch and the third switch and is used for providing a floating power supply for the first switch and the second switch;
the isolation driving circuit is connected with a first power supply, the first switch, the second switch, the third switch and the isolation power supply and is used for providing the action signals for the coil of the first switch and the coil of the second switch after action so as to make the first switch and the second switch act;
and the switch control circuit is connected with the isolation driving circuit and the third switch and used for generating a control signal according to the test trigger signal and controlling the isolation driving circuit to act so as to generate the action signal or control the third switch to act.
In one embodiment, the isolated power supply is configured to:
the first end is connected with the isolation driving circuit, the second end is connected with the first coil port of the first switch, the first coil port of the second switch, the first contact of the third switch and the first power supply, the third end is grounded, and the fourth end is connected with the second power supply.
In one embodiment, the isolation drive circuit is configured to:
the first end is connected with the first end of the isolation power supply, the second end is connected with the second coil port of the second switch, the third end is connected with the second coil port of the first switch, and the fourth end, the fifth end and the sixth end are all connected with the switch control circuit.
In one embodiment, the switch control circuit is configured to:
the first end is connected with the second coil port of the third switch, the second end is connected with the sixth end of the isolation driving circuit, the third end is connected with the fifth end of the isolation driving circuit, the fourth end is connected with the fourth end of the isolation driving circuit, and the fifth end is grounded.
In one embodiment, the switch isolation control circuit comprises a first controllable switch unit, a second controllable switch unit, a third controllable switch unit and a current limiting resistor;
the first controllable switch unit is configured to: the first pole is connected with the fourth end of the isolation driving circuit, and the second pole is grounded;
the second controllable switch unit is configured to: the first pole is connected with the fifth end of the isolation driving circuit, and the second pole is grounded;
the third controllable switch unit is configured to: the first pole is connected with the second coil port of the third switch, and the second pole is grounded;
the current limiting resistor is connected in series between a third power supply and the sixth end of the isolation driving circuit.
In one embodiment, the method further comprises the following steps:
and the equipotential circuit unit is used for shielding the external leakage current of the integrated circuit test circuit.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the description of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of a test circuit according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a test circuit according to an embodiment of the present application;
FIG. 3 is a schematic diagram of the operation of a test circuit according to an embodiment of the present application;
FIG. 4 is a schematic diagram of the operation of a test circuit according to another embodiment of the present application;
FIG. 5 is a schematic diagram of a floating control circuit according to an embodiment of the present application;
FIG. 6 is a schematic diagram of a test circuit according to another embodiment of the present application;
fig. 7 is a schematic structural diagram of a test circuit of a three-pin semiconductor discrete device in an embodiment of the present application.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", or the like, if there is a transfer of electrical signals or data between the connected objects.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.
In the production process of the semiconductor device, due to the limitation of process factors, certain defects can be generated inside the semiconductor discrete device, and the defects can generate parasitic effects when the semiconductor discrete device works to form a parasitic device. The parasitic device can cause the increase of the leakage current of the device, further cause the static power loss of the semiconductor discrete device, influence the performance of the device, and even cause the circuit failure in serious cases. Therefore, in the production test of semiconductor discrete devices, the leakage current test is an indispensable link, and the magnitude of the leakage current of a tested Device (DUT) is usually in the nA level or even the pA level.
In the semiconductor test link, besides the pin leakage current test, the test also includes the test of other parameters, in the modern large-scale industrial production, in order to improveThe test efficiency is usually realized by adopting a switch switching circuit to meet the circuit switching requirements during different parameter tests, and corresponding DUT parameter tests are carried out under different working states of a switch. However, due to the influence of parasitic effect, leakage resistance exists between the coil and the contact of the switch, the size is usually between 10G Ω to 10T Ω, and the magnitude of the switch leakage current is in the order of nA to pA, as shown in fig. 1, the equivalent resistance circuit diagram of the switch leakage current testing circuit is shown, the leakage resistance R1 of the switch is incorporated into the testing circuit after the switch is closed, and the current value actually measured by the testing instrument is I m ＝I t +I 1 Wherein, I t For DUT leakage current, I 1 For the switch leakage current, since the two are of the same order, the switch leakage current I 1 Will seriously affect the DUT leakage current I t The accuracy of the test, how to minimize or even eliminate the influence is an important problem to be solved by adopting a switch switching circuit in the test of the semiconductor device.
In order to solve the above problems, the present application provides a test circuit and a test apparatus, which will be described below by specific embodiments.
In an embodiment of the present application, please refer to fig. 1, which provides a test circuit, including a switch module 300, a measurement apparatus 100 and a floating control circuit 200, wherein the switch module 300 is configured to control a device under test to access a corresponding test circuit according to an action signal, so that the test circuit reaches a corresponding operating state; the measuring device 100 is connected to the switch module 300, and is configured to measure a leakage current of the device under test; the floating control circuit 200 is connected to both the switch module 300 and the measurement apparatus 100, and is configured to provide an action signal to the coil of the switch module 300 according to the action of the received test trigger signal, so as to control the action of the switch module 300.
Specifically, the switch action signal includes a leakage current test action signal and other test action signals, the corresponding test circuit includes a leakage current test circuit and other test circuits, and the switch module 300 controls the DUT to be connected to the corresponding test circuit according to different switch action signals, so as to implement efficient test switching.
Further, in some embodiments, the testing apparatus 100 is a nanoampere meter or a picoampere meter connected in series with the testing power supply, which can be selected according to the magnitude of the leakage current.
In the test circuit provided in the above embodiment, the floating control circuit is arranged to independently control the switch coil, and the switch coil is separated from the normal test circuit, so that the influence of the switch on the test circuit can be reduced to the greatest extent, and the isolation power supply with the voltage value far smaller than that of the test power supply is arranged in the floating control circuit, so as to provide a working power supply for the switch coil, and greatly reduce the voltage at two ends of the leakage resistance of the switch, thereby greatly reducing the influence of the leakage current of the switch on the leakage current of a device to be tested.
In one embodiment of the present application, referring to fig. 2, the switch module 300 includes:
a first switch 310 configured to: the first contact is connected with a first power supply V1 through the measuring device 100, the second contact is connected with a device to be tested DUT, and the first coil port and the second coil port are both connected with the floating control circuit 200;
specifically, the first switch 310 is closed according to the leakage current test action signal to control the DUT to be connected to the leakage current test circuit, or is opened according to another test action signal to disconnect the DUT from the leakage current test circuit.
A second switch 320 configured to: the first contact is connected with a second contact of the first switch 310, the second contact is connected with other test circuits, and the first coil port and the second coil port are both connected with the floating control circuit 200;
specifically, the second switch 320 is opened according to the leakage current test action signal to cut off the connection of the DUT to other test circuits or closed according to other test action signals to control the DUT to access the test loops of other test circuits.
A third switch 330 configured to: the first contact is connected to both the first power supply V1 and the floating control circuit 200, the second contact is connected to the second contact of the second switch 320, the first coil port is connected to the second power supply V2, and the second coil port is connected to the floating control circuit 200.
Specifically, the third switch 330 is closed according to the leakage current test action signal to short the first contact of the second switch 320 with the second contact of the second switch 320, or is opened according to other test action signals.
In one embodiment of the present application, with continued reference to fig. 2, the floating control circuit 200 includes:
the isolation power supply 210 is connected with the first power supply V1, the second power supply V2, the first switch 310, the second switch 320 and the third switch 330, and is used for providing floating power for the first switch 310 and the second switch 320;
specifically, the isolated power supply 210 is configured to: the second terminal is connected to the first coil port of the first switch 310, the first coil port of the second switch 320, the first contact of the third switch 330, and the first power source V1, the third terminal is grounded, and the fourth terminal is connected to the second power source V2.
An isolation driving circuit 220, connected to the first power source V1, the first switch 310, the second switch 320, the third switch 330 and the isolation power source 210, for providing an operation signal to the coil of the first switch 310 and the coil of the second switch 320 after operation, so as to operate the first switch 310 and the second switch 320;
specifically, the isolation drive circuit 220 is configured to: the first terminal is connected to the first terminal of the isolation power supply 210, the second terminal is connected to the second coil port of the second switch 320, and the third terminal is connected to the second coil port of the first switch 310.
The switch control circuit 230 is connected to both the isolation driving circuit 220 and the third switch 330, and is configured to generate a control signal according to the test trigger signal, control the isolation driving circuit 220 to operate to generate an operation signal, or control the third switch 330 to operate.
Specifically, the switch control circuit 230 is configured to: the first end is connected to the second coil port of the third switch 330, the second end is connected to the sixth end of the isolation driving circuit 220, the third end is connected to the fifth end of the isolation driving circuit 220, the fourth end is connected to the fourth end of the isolation driving circuit 220, and the fifth end is grounded.
Further, the tester sends a test trigger signal to the switch control circuit 230 according to the test requirement, and the switch control circuit 230 determines what kind of test is performed according to the test trigger signal, so as to generate a corresponding control signal, and sends a corresponding action signal to the third switch 330 and the isolation driving circuit 220, respectively, so as to control the switch inside the switch module 300 to complete a corresponding opening and closing action, so as to control the DUT to access the corresponding test circuit.
In an embodiment of the present application, please refer to fig. 3, the circuit operates in a leakage current test state, in which the resistor R1 is an equivalent leakage resistance between the coil and the contact of the first switch 310, the resistor R2 is an equivalent leakage resistance between the coil and the contact of the second switch 320, and R3 is an equivalent leakage resistance between the contacts of the second switch 320. At this time, the switch control circuit 230 controls the isolation driving circuit 220 to turn on the first switch 310 and turn off the second switch 320, and controls the third switch 330 to turn on, so that the DUT is connected to the leakage current test loop and isolated from other test circuits by the second switch 320.
Specifically, due to the existence of the equivalent leakage resistances R1, R2 and R3, when the measuring device 100 measures the leakage current of the DUT, the leakage current passing through the equivalent leakage resistances R1, R2 and R3 also enters the measuring device 100, resulting in a large error in measuring the leakage current of the DUT, i.e., I m ＝I t +I 1 +I 2 +I 3 Wherein, I 1 Is a leakage current of equivalent leakage resistance R1 2 Is a leakage current of equivalent leakage resistance R2 3 How to reduce I for equivalent leakage current of leakage resistor R3 1 +I 2 +I 3 The value of (c) is related to the accuracy of the final leakage current measurement. As can be seen from the circuit structure shown in fig. 3, since the measuring device 100 is a nanoampere meter or a picoampere meter and the internal resistance is neglected, the voltage value at both ends of the equivalent leakage resistance R1 is V1, and the voltage difference Δ U is 1 0V, so that I 1 When the term is equal to 0A, the same principle can be usedTo obtain I 2 ＝0A，I 3 When the floating power supply is supplied to the switch module 300 through the floating control circuit 200, the leakage current generated at the switch terminal can be set to 0, and only the leakage current flowing through the DUT remains in the readout of the measurement apparatus 100, so that the current value measured by the measurement apparatus 100 can accurately reflect the actual leakage current of the DUT.
In an embodiment of the present application, referring to fig. 4, when the circuit works in other test states, the switch control circuit 230 controls the isolation driving circuit 220 to turn off the first switch 310 and turn on the second switch 320, and controls the third switch 330 to turn off, so that the DUT is connected to other test circuits, and is isolated from the leakage current test circuit by the first switch 310 and the third switch 330.
In an embodiment of the present application, referring to fig. 5, in a schematic structural diagram of a floating control circuit provided in the present application, the isolation driving circuit 220 is two photo-couplers, and the switch control circuit 230 includes: a first controllable switch unit K1, a second controllable switch unit K2, a third controllable switch unit K3 and a current limiting resistor R, wherein the first controllable switch unit K1 is configured to: the first pole is connected with the fourth end of the isolation driving circuit 220, and the second pole is grounded; the second controllable switch unit K2 is configured to: the first pole is connected to the fifth end of the isolation driving circuit 220, and the second pole is grounded; the third controllable switch unit K3 is configured to: the first pole is connected with the second coil port of the third switch 330, and the second pole is grounded; the current limiting resistor R is connected in series between the third power source V3 and the sixth terminal of the isolated driving circuit 220.
Specifically, the photocoupler is a commonly used optoelectronic isolator, and contains a light emitting diode, when the photocoupler works, the light emitting diode is turned on and emits light with a fixed wavelength, and the light emitting diode is received by the photodetector to generate a photocurrent, and the photocurrent is further amplified and then output, and is often used in the situation where signal isolation is needed, in this embodiment, a tester sends a test trigger signal to the switch control circuit 230 through a control center to respectively control the first controllable switch unit K1, the second controllable switch unit K2, and the third controllable switch unit K3 to work normally, and further control the isolation driving circuit 220 and the third switch 330 to work normally, and voltage isolation is performed through the photocoupler in the isolation driving circuit 220, so that the coil driving voltages of the first switch 310 and the second switch 320 float on the first power supply V1 without interference.
In an embodiment of the present application, as shown in fig. 6, the present application further provides a test circuit including an equipotential circuit unit 400, where the equipotential circuit unit 400 is used to shield leakage current from the test circuit to the outside, and in this embodiment, the equipotential circuit unit may adopt a guard protection circuit.
In particular, electrostatic discharge (ESD) is usually generated by contact, friction, and induction between electrical devices, and is characterized by long-time accumulation, high voltage (Static electricity of thousands of volts or even tens of thousands of volts can be generated), low electric quantity, small current, and short action time. For electronic products, if the ESD design is not well designed, the electronic products are often unstable and even damaged. In this regard, guard protection circuits may be employed in circuit design to prevent the lines from discharging to ground through parasitic devices due to electrostatic buildup, which can cause a number of problems.
Furthermore, the guard protection circuit is led out from the low impedance end of the measuring device close to the power supply position of the first power supply to form a low impedance ground connection, so that the influence of the impedance of other power supply circuits passing through the PCB on the leakage current test circuit can be reduced, and the influence of electromagnetic radiation in a shielding space on the leakage current test circuit can be shielded. In this embodiment, the leading-out line of the guard protection circuit 400 is led out from the low impedance end of the measuring apparatus 100 close to the power supply of the first power supply V1 to form a low impedance ground connection, thereby reducing the influence of the impedance of other test circuits through the PCB on the leakage current test circuit and shielding the influence of electromagnetic radiation in space on the leakage current test circuit.
In an embodiment of the present application, as shown in fig. 7, the present application provides a schematic diagram of a test circuit structure of a three-pin discrete semiconductor device, and compared with a two-pin discrete semiconductor device, a test circuit from a first pin to a common pin is the same as a test circuit from a second pin to the common pin, and can be symmetrically arranged, while a ground leakage current of the common pin is eliminated by arranging a seventh switch to be directly shorted to ground on one hand, and a guard protection circuit is arranged on the second hand to discharge a parasitic leakage current of a common pin end to ground, so that the leakage current of the common pin end does not affect a leakage current test of the first pin and the second pin to the common pin.
It should be noted that, in the embodiments provided in the present application, it should be understood that the disclosed technical contents may be implemented in other manners. The above-described system embodiments are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be an indirect coupling or communication connection through some interfaces, units or modules, and may be electrical or in other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be implemented in a hardware form.
Finally, the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting, although the present application is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present application without departing from the spirit and scope of the technical solutions, and all that should be covered by the claims of the present application.
Claims (10)
1. A test circuit, comprising:
the switch module is used for controlling the device to be tested to be connected into the corresponding test circuit according to the action signal so as to enable the test circuit to reach the corresponding working state;
the measuring device is connected with the switch module and used for measuring the leakage current of the device to be measured;
and the floating control circuit is connected with the switch module and the measuring device and used for providing the action signal for the switch module according to the action of the received test trigger signal so as to control the action of the switch module.
2. The circuit of claim 1, wherein the action signals comprise a leakage current test action signal and other test action signals, and the switch module comprises:
a first switch configured to: the first contact is connected with a first power supply through the measuring device, the second contact is connected with the device to be tested, and the first coil port and the second coil port are both connected with the floating control circuit;
the first switch is further configured to: the device to be tested is controlled to be connected to a leakage current test circuit by closing according to the leakage current test action signal, or the device to be tested is controlled to be connected to the leakage current test circuit by opening according to the other test action signals;
a second switch configured to: the first contact is connected with the second contact of the first switch, the second contact is connected with other test circuits, and the first coil port and the second coil port are both connected with the floating control circuit;
the second switch is further configured to: according to the leakage current test action signal, the connection between the device to be tested and the other test circuits is cut off, or according to the other test action signals, the connection is closed, so that the device to be tested is controlled to be connected to the test loops of the other test circuits;
a third switch configured to: the first contact is connected with both the first power supply and the floating control circuit, the second contact is connected with the second contact of the second switch, the first coil port is connected with the second power supply, and the second coil port is connected with the floating control circuit;
the third switch is further configured to: and closing according to the leakage current test action signal to enable the first contact of the second switch and the second contact of the second switch to be in short circuit through the measuring device, or opening according to the other test action signals.
3. The circuit of claim 2, wherein the operating state comprises a leakage current test operating state, and wherein the switching module is configured to:
the first switch is closed, the second switch is opened, the third switch is closed, and the test circuit enters a leakage current test working state.
4. The circuit of claim 3, wherein the operating state comprises other test operating states, the switch module configured to:
the first switch is opened, the second switch is closed, the third switch is opened, and the test circuit enters other test working states.
5. The circuit of claim 2, wherein the floating control circuit comprises:
the isolation power supply is connected with the first power supply, the second power supply, the first switch, the second switch and the third switch and is used for providing a floating power supply for the first switch and the second switch;
the isolation driving circuit is connected with a first power supply, the first switch, the second switch, the third switch and the isolation power supply and is used for providing the action signals for the coil of the first switch and the coil of the second switch after action so as to make the first switch and the second switch act;
and the switch control circuit is connected with the isolation driving circuit and the third switch and used for generating a control signal according to the test trigger signal and controlling the isolation driving circuit to act so as to generate the action signal or control the third switch to act.
6. The circuit of claim 5, wherein the isolated power supply is configured to:
the first end is connected with the isolation driving circuit, the second end is connected with the first coil port of the first switch, the first coil port of the second switch, the first contact of the third switch and the first power supply, the third end is grounded, and the fourth end is connected with the second power supply.
7. The circuit of claim 6, wherein the isolation drive circuit is configured to:
the first end is connected with the first end of the isolation power supply, the second end is connected with the second coil port of the second switch, the third end is connected with the second coil port of the first switch, and the fourth end, the fifth end and the sixth end are all connected with the switch control circuit.
8. The circuit of claim 7, wherein the switch control circuit is configured to:
the first end is connected with the second coil port of the third switch, the second end is connected with the sixth end of the isolation driving circuit, the third end is connected with the fifth end of the isolation driving circuit, the fourth end is connected with the fourth end of the isolation driving circuit, and the fifth end is grounded.
9. The circuit of claim 8, wherein the switch isolation control circuit comprises a first controllable switch unit, a second controllable switch unit, a third controllable switch unit and a current limiting resistor;
the first controllable switch unit is configured to: the first pole is connected with the fourth end of the isolation driving circuit, and the second pole is grounded;
the second controllable switch unit is configured to: the first pole is connected with the fifth end of the isolation driving circuit, and the second pole is grounded;
the third controllable switch unit is configured to: the first pole is connected with the second coil port of the third switch, and the second pole is grounded;
the current limiting resistor is connected in series between a third power supply and the sixth end of the isolation driving circuit.
10. The circuit of any one of claims 1-9, further comprising:
and the equipotential circuit unit is used for shielding the external leakage current of the test circuit.
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| CN202122721584.XU CN217404462U (en) | 2021-11-08 | 2021-11-08 | Test circuit |
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| CN202122721584.XU CN217404462U (en) | 2021-11-08 | 2021-11-08 | Test circuit |
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2021
- 2021-11-08 CN CN202122721584.XU patent/CN217404462U/en active Active
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