Test circuit, test method and test system

Abstract

The application relates to a test circuit, a test method and a test system. The test circuit comprises a detection line, a controllable power supply detection module and a detection line. The detection line comprises a first detection line, a second detection line, a third detection line and a fourth detection line. The first end of the first detection line and the first end of the third detection line are respectively connected with a first output end of a measured circuit. The first end of the second detection line and the first end of the fourth detection line are respectively connected with a second output end of the measured circuit. The controllable power supply detection module is connected with the second end of the first detection line, the second end of the second detection line, the second end of the third detection line and the second end of the fourth detection line. The controllable power supply detection module is used for detecting the voltage value between the first output end and the second output end through the third detection line and the fourth detection line in an open circuit working mode. The controllable power supply detection module is also used for detecting the current value flowing through the first output end and the second output end through the first detection line and the second detection line in a zero voltage working mode. The test circuit has the advantages of high test precision.

Description

Technical Field

[0001] This application relates to the field of circuit testing technology, and in particular to a test circuit, test method and test system. Background Technology

[0002] For circuits that use constant current source drive and dual-port output, when testing the circuit parameters at the output terminal, a high-precision resistor is usually connected in series at the output terminal. By measuring the voltage and current across the high-precision resistor, the current and output resistance at the circuit output terminal can be calculated to determine whether they meet the requirements.

[0003] However, in mass production testing, the uncertainty of the contact resistance of each chip, as well as the error resistance of the traces and external environment, can cause large errors in the test results. Summary of the Invention

[0004] Therefore, it is necessary to provide a test circuit, test method, and test system with high testing accuracy.

[0005] In a first aspect, this application provides a test circuit, including:

[0006] The test line includes a first test line, a second test line, a third test line, and a fourth test line. The first end of the first test line and the first end of the third test line are respectively connected to the first output terminal of the circuit under test, and the first end of the second test line and the first end of the fourth test line are respectively connected to the second output terminal of the circuit under test.

[0007] A controllable power supply detection module is connected to the second ends of the first detection line, the second end of the second detection line, the second end of the third detection line, and the second end of the fourth detection line, respectively. The controllable power supply detection module includes an open-circuit operating mode and a zero-voltage operating mode.

[0008] The controllable power supply detection module is used to detect the voltage value between the first output terminal and the second output terminal through the third detection line and the fourth detection line when the open circuit operation mode is in operation; and to control the voltage between the first output terminal and the second output terminal to be 0 when the zero voltage operation mode is in operation, and to detect the current value flowing through the first output terminal and the second output terminal through the first detection line and the second detection line; in the open circuit operation mode, the first detection line and the second detection line are in a high resistance state, and the third detection line and the fourth detection line are also in a high resistance state.

[0009] In one embodiment, the circuit under test includes a driving module and an output module; the driving module includes a constant current source connected to the output module for providing a current driving signal;

[0010] The output module is used to output a first output signal through the first output terminal and a second output signal through the second output terminal under the drive of the current driving signal.

[0011] The voltage value is the potential difference between the first output signal and the second output signal; the current value is the current value of the current driving signal.

[0012] In one embodiment, the output module includes two output units, each of which includes a first switching transistor and a second switching transistor;

[0013] In the same output unit, the first terminal of the first switch is connected to the driving module, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive a first control signal, and the control terminal of the second switch is used to receive a second control signal; wherein...

[0014] The first end of the first detection line and the first end of the third detection line are respectively connected to the second end of the first switch in one of the output units, and the first end of the second detection line and the first end of the fourth detection line are respectively connected to the second end of the first switch in another output unit.

[0015] In one embodiment, the controllable power supply detection module is further configured to determine the resistance value of the matching resistor in the circuit under test based on the current value and the voltage value.

[0016] Secondly, this application provides a testing method applied to the testing circuit provided in any of the above embodiments, the method comprising:

[0017] Connect the first and third detection lines in the test circuit to the first output terminal of the output module in the circuit under test, and connect the second and fourth detection lines in the test circuit to the second output terminal of the output module in the circuit under test.

[0018] The controllable power supply detection module in the test circuit is controlled to operate in open circuit mode, and the voltage value between the first output terminal and the second output terminal is detected through the third detection line and the fourth detection line;

[0019] The controllable power supply detection module is controlled to operate in a zero-voltage mode, and the current value flowing through the first output terminal and the second output terminal is detected through the first detection line and the second detection line.

[0020] In one embodiment, the circuit under test includes a connected constant current source and an output module;

[0021] The method further includes:

[0022] The constant current source is controlled to output a current driving signal to the output module, so that the output module outputs a first output signal through the first output terminal and a second output signal through the second output terminal under the drive of the current driving signal;

[0023] Wherein, the voltage value is the potential difference between the first output signal and the second output signal;

[0024] The current value is the current value of the current driving signal.

[0025] In one embodiment, the method further includes:

[0026] The resistance value of the matching resistor in the circuit under test is determined based on the current value and the voltage value.

[0027] Thirdly, this application provides a testing system, including:

[0028] The circuit under test;

[0029] The test circuit includes detection lines and a controllable power supply detection module; among which,

[0030] The detection line includes a first detection line, a second detection line, a third detection line, and a fourth detection line. The first end of the first detection line and the first end of the third detection line are respectively used to connect to the first output terminal, and the first end of the second detection line and the first end of the fourth detection line are respectively used to connect to the second output terminal.

[0031] The controllable power supply detection module is used to connect to the second terminals of the first detection line, the second detection line, the third detection line, and the fourth detection line, respectively; the controllable power supply detection module includes an open-circuit operating mode and a zero-voltage operating mode; wherein...

[0032] The controllable power supply detection module is used to detect the voltage value between the first output terminal and the second output terminal through the third detection line and the fourth detection line in the open circuit operation mode; and to control the voltage between the first output terminal and the second output terminal to be 0 in the zero voltage operation mode, and to detect the current value flowing through the first output terminal and the second output terminal through the first detection line and the second detection line; in the open circuit operation mode, the first detection line and the second detection line are in a high resistance state, and the third detection line and the fourth detection line are also in a high resistance state.

[0033] In one embodiment, the circuit under test includes at least a driving module, an output module, and a matching module;

[0034] The driving module is connected to the output module and is used to drive the output module;

[0035] The output module includes a first output terminal and a second output terminal;

[0036] The matching module is connected in series between the first output terminal and the second output terminal.

[0037] In one embodiment, the driving module includes a constant current source connected to the output module, the constant current source being used to provide a current driving signal;

[0038] The output module includes two output units, and each output unit includes a first switching transistor and a second switching transistor.

[0039] In the same output unit, the first terminal of the first switch is connected to the driving module, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive a first control signal, and the control terminal of the second switch is used to receive a second control signal; wherein...

[0040] The first end of the first detection line and the first end of the third detection line are respectively connected to the second end of the first switch in one of the output units, and the first end of the second detection line and the first end of the fourth detection line are respectively connected to the second end of the first switch in another output unit.

[0041] In the aforementioned test circuit, test method, and test system, the drive signal for the circuit under test (DUT) is provided by the internal drive module of the DUT. The controllable power supply detection module primarily functions as a voltmeter and ammeter. Without altering the original operating state of the DUT, it detects the current flowing through the first and second output terminals via the first and second detection lines, and detects the voltage between the first and second output terminals via the third and fourth detection lines, enabling online monitoring of the DUT. Furthermore, the first detection line, the DUT, the second detection line, and the controllable power supply detection module constitute a current detection loop. By setting the controllable power supply detection module to zero-voltage operating mode, the voltage between the first and second output terminals is clamped to 0V. At this time, the current flowing through the controllable power supply detection module via the first or second detection line is the current flowing through the first and second output terminals. The current flowing through the first and second output terminals can be directly measured using the ammeter function of the controllable power supply detection module. The third detection line, the DUT, the fourth detection line, and the controllable power supply detection module constitute a voltage detection loop, while the current detection loop and voltage detection loop are separate. By setting the controllable power supply detection module of the test circuit to open-circuit operation mode, the first and second detection lines are in a high-resistance state, as are the third and fourth detection lines. In this way, the first and second detection lines are equivalent to an open circuit, and the third and fourth detection lines have extremely high resistance, almost absorbing no current. The voltage drop caused by the test leads is negligible. The voltmeter function of the controllable power supply detection module can be directly used to detect the voltage value between the first and second output terminals through the third and fourth detection lines. This can effectively eliminate the errors caused by the test leads and contact resistance, and improve the accuracy of current and voltage detection results. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A schematic diagram of the structure of a test circuit provided in one embodiment;

[0044] Figure 2 This is a schematic diagram of the structure of the circuit under test provided in one embodiment;

[0045] Figure 3 A schematic diagram of the structure of an output module provided in one embodiment;

[0046] Figure 4A flowchart of a test method provided in one embodiment;

[0047] Figure 5 This is a connection diagram of the test circuit and the LVDS circuit provided in one embodiment;

[0048] Figure 6 A schematic diagram of the circuit under test provided for another embodiment. Detailed Implementation

[0049] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0050] Unless otherwise defined, 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 herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0051] It is understood that the terms "first," "second," etc., used in this application 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. For example, without departing from the scope of this application, a first detection line may be referred to as a second detection line, and similarly, a second detection line may be referred to as a first detection line. Both the first detection line and the second detection line are detection lines, but they are not the same detection line.

[0052] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0053] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0054] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0055] In one embodiment, this application provides a test circuit, such as... Figure 1 As shown, it can be used to measure the current and voltage values ​​at the output terminal of the circuit under test 100. The circuit under test 100 can be a circuit with a power supply and a closed-loop configuration, such as a low voltage differential signaling (LVDS) circuit, which has a constant current source and a closed-loop configuration.

[0056] The test circuit may include detection lines and a controllable power supply detection module 220. The detection lines may include a first detection line 211, a second detection line 212, a third detection line 213, and a fourth detection line 214. The first ends of the first detection line 211 and the third detection line 213 are respectively connected to the first output terminal of the circuit under test 100, and the first ends of the second detection line 212 and the fourth detection line 214 are respectively connected to the second output terminal of the circuit under test 100. The controllable power supply detection module 220 is connected to the second ends of the first detection line 211, the second detection line 212, the third detection line 213, and the fourth detection line 214. The first detection line 211 and the second detection line 212 can be FORCE_H and FORCE_L lines, respectively, and the third detection line 213 and the fourth detection line 214 can be SENSE_H and SENSE_L lines, respectively.

[0057] The controllable power supply detection module 220 can be used to detect the current flowing through the first output terminal and the second output terminal via the first detection line 211 and the second detection line 212, and to detect the voltage between the first output terminal and the second output terminal via the third detection line 213 and the fourth detection line 214. The controllable power supply detection module 220 can function as a voltage source, voltmeter, current source, and ammeter, and can be switched via an internal logic control unit. For example, the controllable power supply detection module 220 can be a V / I source / meter.

[0058] The controllable power supply detection module 220 includes an open-circuit operating mode and a zero-voltage operating mode.

[0059] The controllable power supply detection module 220 is used to detect the voltage between the first output terminal and the second output terminal through the third detection line 213 and the fourth detection line 214 when operating in open-circuit mode. In open-circuit mode, the first detection line 211 and the second detection line 212 are in a high-resistance state, and the third detection line 213 and the fourth detection line 214 are also in a high-resistance state. The first detection line 211 and the second detection line 212 are equivalent to an open circuit, and the third detection line 213 and the fourth detection line 214 have extremely high resistance and hardly absorb current. The voltage drop caused by the test leads is negligible.

[0060] The controllable power supply detection module 220 is used to control the voltage between the first and second output terminals to 0V when operating in zero-voltage mode, and to detect the current flowing through the first and second output terminals via the first detection line 211 and the second detection line 212. In zero-voltage mode, the controllable power supply detection module 220 can acquire the voltage between the first and second output terminals via the third detection line 213 and the fourth detection line 214. Through an internal closed-loop feedback network, it controls the potential of the first and second detection lines 211 and 212, clamping the voltage between the first and second output terminals to 0V. At this time, the current flowing through the controllable power supply detection module 220 via the first detection line 211 or the second detection line 212, i.e., the current flowing through the first and second output terminals, can be directly measured using the ammeter function of the controllable power supply detection module 220.

[0061] In this embodiment, the first detection line 211, the circuit under test, the second detection line 212, and the controllable power supply detection module 220 constitute a current detection loop. By setting the controllable power supply detection module 220 to a zero-voltage operating mode, the voltage between the first output terminal and the second output terminal is clamped to 0V. At this time, the current flowing through the controllable power supply detection module 220 through the first detection line 211 or the second detection line 212 is the current value passing through the first output terminal and the second output terminal. The current value passing through the first output terminal and the second output terminal can be directly measured using the ammeter function of the controllable power supply detection module 220. The third detection line 213, the circuit under test, the fourth detection line 214, and the controllable power supply detection module 220 constitute a voltage detection loop. By setting the controllable power supply detection module of the test circuit... Block 220 is set to open-circuit operation mode, making the first detection line 211 and the second detection line 212 in a high-resistance state, and the third detection line 213 and the fourth detection line 214 also in a high-resistance state. In this way, the first detection line 211 and the second detection line 212 are equivalent to an open circuit, and the third detection line 213 and the fourth detection line 214 have extremely high resistance and hardly absorb current. The voltage drop caused by the test leads is negligible. The voltmeter function of the controllable power supply detection module 220 can be directly used to detect the voltage value between the first output terminal and the second output terminal through the third detection line 213 and the fourth detection line 214. The current detection circuit and the voltage detection circuit are separated, which can effectively eliminate the error caused by the test leads and contact resistance, and improve the accuracy of the current detection result and the voltage detection result.

[0062] In one embodiment, such as Figure 2As shown, the circuit under test 100 includes a drive module 110 and an output module 120. The drive module 110 includes a constant current source. The constant current source is connected to the output module 120 and can be used to provide a current drive signal. The output module 120 is used to output a first output signal through a first output terminal and a second output signal through a second output terminal under the drive of the current drive signal. The first output signal and the second output signal have different potentials.

[0063] In this embodiment, the voltage value measured by the test circuit is the potential difference between the first output signal and the second output signal, and the current value measured is the current value of the current drive signal. It can be understood that the drive signal of the circuit under test is provided by the constant current source in the circuit under test 100. By utilizing only the voltmeter and ammeter functions of the controllable power supply detection module 220, the original operating state of the circuit under test 100 can be unchanged, thus enabling online monitoring of the circuit under test 100.

[0064] In one embodiment, such as Figure 3 As shown, the output module 120 includes two output units, each of which includes a first switch and a second switch.

[0065] In the same output unit, the first terminal of the first switch is connected to the drive module 110, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive the first control signal, and the control terminal of the second switch is used to receive the second control signal. The first switch and the second switch are not turned on simultaneously.

[0066] The first end of the first detection line 211 and the first end of the third detection line 213 are respectively connected to the second end of the first switching transistor in an output unit, and the first end of the second detection line 212 and the first end of the fourth detection line 214 are respectively connected to the second end of the first switching transistor in another output unit.

[0067] In this embodiment, the first detection line 211, the second detection line 212, the third detection line 213 and the fourth detection line 214 are not directly grounded, but are respectively connected to the common connection terminal of the output unit. This avoids introducing ground parameters into the test line, reduces common-mode interference and improves measurement accuracy.

[0068] In one embodiment, the circuit under test further includes a matching resistor, which can be connected in series between the first output terminal and the second output terminal. The controllable power supply detection module 220 is also used to determine the resistance value of the matching resistor in the circuit under test based on the measured current and voltage values.

[0069] In this embodiment, the controllable power supply detection module 220 also has a resistance measurement function, which can calculate the resistance value of the matching resistor based on the quotient of the previously measured voltage and current values.

[0070] Based on the same inventive concept, this application also provides a testing method, which can be applied to the test circuit provided in any of the above embodiments, such as... Figure 4 As shown, the test method includes:

[0071] S100, connect the first detection line and the third detection line in the test circuit to the first output terminal of the circuit under test, and connect the second detection line and the fourth detection line in the test circuit to the second output terminal of the circuit under test.

[0072] S200, the controllable power supply detection module in the control test circuit operates in open circuit mode, and detects the voltage value between the first output terminal and the second output terminal through the third detection line and the fourth detection line.

[0073] S300 controls the controllable power supply detection module to operate in zero-voltage mode, and detects the current value flowing through the first output terminal and the second output terminal through the first detection line and the second detection line.

[0074] In this embodiment, by setting the controllable power supply detection module 220 of the test circuit to open-circuit operation mode, the first detection line 211 and the second detection line 212 are in a high-resistance state, and the third detection line 213 and the fourth detection line 214 are also in a high-resistance state. Thus, the first detection line 211 and the second detection line 212 are equivalent to an open circuit, and the third detection line 213 and the fourth detection line 214 have extremely high resistance, almost absorbing no current. The voltage drop from the test leads is negligible, and the voltmeter function of the controllable power supply detection module 220 can be directly utilized through the third detection line 213. The fourth detection line 214 detects the voltage value between the first output terminal and the second output terminal, thereby improving the accuracy of voltage detection. By setting the controllable power supply detection module 220 to zero-voltage operating mode, the voltage between the first output terminal and the second output terminal is clamped to 0V. At this time, the current flowing through the controllable power supply detection module 220 through the first detection line 211 or the second detection line 212 is the current value through the first output terminal and the second output terminal. The current value through the first output terminal and the second output terminal can be directly measured using the ammeter function of the controllable power supply detection module 220, which is simple to operate.

[0075] In one embodiment, the testing method of this application further includes controlling the constant current source to output a current driving signal to the output module, so that the output module outputs a first output signal through the first output terminal and outputs a second output signal through the second output terminal under the drive of the current driving signal.

[0076] Wherein, the voltage value is the potential difference between the first output signal and the second output signal, and the current value is the current value of the current driving signal.

[0077] It is understandable that the drive signal of the circuit under test is provided by the constant current source in the circuit under test. By only using the voltmeter and ammeter functions of the controllable power supply detection module 220, the original working state of the circuit under test can be changed, and online monitoring of the circuit under test can be achieved.

[0078] In one embodiment, the test method of this application further includes the step of determining the resistance value of the matching resistor in the circuit under test based on the voltage value across the matching module and the current value output by the driving module.

[0079] In this embodiment, since the voltage and current values ​​measured by this application are highly accurate, the resistance values ​​calculated based on these voltage and current values ​​are also highly accurate.

[0080] In one embodiment, the test method provided in this application is illustrated by taking the measurement of circuit parameters of an LVDS circuit using the test circuit of this application as an example.

[0081] LVDS circuits are a high-speed interface technology based on differential signal transmission. They transmit low-amplitude signals through a pair of differential traces or balanced cables and use voltage differences to transmit data.

[0082] like Figure 5 As shown, the first detection line 211 and the third detection line 213 can be connected to one end of the resistor R1 in the LVDS circuit, and the second detection line 212 and the fourth detection line 214 can be connected to the other end of the resistor R1 in the LVDS circuit. The controllable power supply detection module 220 in the test circuit is set to open-circuit output mode, and the voltage across the resistor R1 is detected using the third detection line 213 and the fourth detection line 214. The controllable power supply detection module 220 is then set to 0V output mode, and the current flowing through the resistor R1, i.e., the current output by the constant current source, is detected using the first detection line 211 and the second detection line 212. Based on Ohm's law, the quotient of the measured voltage and current values ​​is determined as the resistance value of R1. Thus, the measured current value can be compared with the target value (e.g., 3.5mA), and the resistance value of R1 can be compared with the target value (e.g., 100Ω) to determine whether the circuit meets the design requirements.

[0083] Clearly, the test method of this application is simple to operate and can eliminate the voltage drop caused by the test leads and contact resistance, making the test results more accurate.

[0084] Based on the same inventive concept, this application also provides a testing system. The solution provided by this testing system is similar to the solution described in the above-described testing circuit. Therefore, the specific limitations of the one or more testing system embodiments provided below can be found in the limitations of the testing circuit described above, and will not be repeated here.

[0085] In one embodiment, such as Figure 1 As shown, the test system includes the circuit under test 100 and the test circuit.

[0086] The test circuit includes a detection line and a controllable power supply detection module 220.

[0087] The detection lines include a first detection line 211, a second detection line 212, a third detection line 213, and a fourth detection line 214. The first end of the first detection line 211 and the first end of the third detection line 213 are respectively connected to the first output terminal of the circuit under test 100, and the first end of the second detection line 212 and the first end of the fourth detection line 214 are respectively connected to the second output terminal of the circuit under test 100.

[0088] The controllable power supply detection module 220 is connected to the second end of the first detection line 211, the second end of the second detection line 212, the second end of the third detection line 213, and the second end of the fourth detection line 214, respectively.

[0089] The controllable power supply detection module 220 includes an open-circuit operating mode and a zero-voltage operating mode.

[0090] The controllable power supply detection module 220 can be used to detect the voltage value between the first output terminal and the second output terminal through the third detection line 213 and the fourth detection line 214 when it is in open circuit operation mode; and to detect the current value flowing through the first output terminal and the second output terminal through the first detection line 211 and the second detection line 212 when it is in zero voltage operation mode.

[0091] In one embodiment, such as Figure 6 As shown, the circuit under test includes at least a driver module 110, an output module 120, and a matching module 130. The driver module 110 is connected to the output module 120 and is used to drive the output module 120. The output module 120 includes a first output terminal and a second output terminal. The matching module 130 is connected in series between the first output terminal and the second output terminal.

[0092] In one embodiment, such as Figure 3 As shown, the drive module 110 includes a constant current source, which is connected to the output module 120. The constant current source is used to provide a current drive signal.

[0093] The output module includes two output units, each including a first switch and a second switch. In the same output unit, the first terminal of the first switch is connected to the drive module 110, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive a first control signal, and the control terminal of the second switch is used to receive a second control signal.

[0094] The first end of the first detection line 211 and the first end of the third detection line 213 are respectively connected to the second end of the first switching transistor in an output unit, and the first end of the second detection line 212 and the first end of the fourth detection line 214 are respectively connected to the second end of the first switching transistor in another output unit.

[0095] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A test circuit, characterized in that, The test circuit includes: The test line includes a first test line, a second test line, a third test line, and a fourth test line. The first end of the first test line and the first end of the third test line are respectively connected to the first output terminal of the circuit under test, and the first end of the second test line and the first end of the fourth test line are respectively connected to the second output terminal of the circuit under test. A controllable power supply detection module is connected to the second ends of the first detection line, the second end of the second detection line, the second end of the third detection line, and the second end of the fourth detection line, respectively. The controllable power supply detection module includes an open-circuit operating mode and a zero-voltage operating mode. The controllable power supply detection module is used to detect the voltage value between the first output terminal and the second output terminal through the third detection line and the fourth detection line when the open circuit operation mode is in operation; and to control the voltage between the first output terminal and the second output terminal to be 0 when the zero voltage operation mode is in operation, and to detect the current value flowing through the first output terminal and the second output terminal through the first detection line and the second detection line; in the open circuit operation mode, the first detection line and the second detection line are in a high resistance state, and the third detection line and the fourth detection line are also in a high resistance state.

2. The test circuit according to claim 1, characterized in that, The circuit under test includes a driver module and an output module; The driving module includes a constant current source, which is connected to the output module and is used to provide a current driving signal; The output module is used to output a first output signal through the first output terminal and a second output signal through the second output terminal under the drive of the current drive signal; wherein, The voltage value is the potential difference between the first output signal and the second output signal; The current value is the current value of the current driving signal.

3. The test circuit according to claim 2, characterized in that, The output module includes two output units, and each output unit includes a first switching transistor and a second switching transistor. In the same output unit, the first terminal of the first switch is connected to the driving module, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive a first control signal, and the control terminal of the second switch is used to receive a second control signal; wherein... The first end of the first detection line and the first end of the third detection line are respectively connected to the second end of the first switch in one of the output units, and the first end of the second detection line and the first end of the fourth detection line are respectively connected to the second end of the first switch in another output unit.

4. The test circuit according to claim 1, characterized in that, The controllable power supply detection module is also used to determine the resistance value of the matching resistor in the circuit under test based on the current value and the voltage value.

5. A testing method, characterized in that, Applied to the test circuit as described in any one of claims 1-4, the method comprises: Connect the first and third detection lines in the test circuit to the first output terminal of the circuit under test, and connect the second and fourth detection lines in the test circuit to the second output terminal of the circuit under test. The controllable power supply detection module in the test circuit is controlled to operate in open circuit mode, and the voltage value between the first output terminal and the second output terminal is detected through the third detection line and the fourth detection line; The controllable power supply detection module is controlled to operate in a zero-voltage mode, and the current value flowing through the first output terminal and the second output terminal is detected through the first detection line and the second detection line.

6. The test method according to claim 5, characterized in that, The circuit under test includes a connected constant current source and an output module; The method further includes: The constant current source is controlled to output a current driving signal to the output module, so that the output module outputs a first output signal through the first output terminal and a second output signal through the second output terminal under the drive of the current driving signal; Wherein, the voltage value is the potential difference between the first output signal and the second output signal; The current value is the current value of the current driving signal.

7. The test method according to claim 5, characterized in that, The method further includes: The resistance value of the matching resistor in the circuit under test is determined based on the current value and the voltage value.

8. A testing system, characterized in that, include: The circuit under test; The test circuit includes detection lines and a controllable power supply detection module; among which, The detection lines include a first detection line, a second detection line, a third detection line, and a fourth detection line. The first end of the first detection line and the first end of the third detection line are respectively used to connect to the first output terminal of the circuit under test. The first end of the second detection line and the first end of the fourth detection line are respectively used to connect to the second output terminal of the circuit under test. The controllable power supply detection module is used to connect to the second terminals of the first detection line, the second detection line, the third detection line, and the fourth detection line, respectively; the controllable power supply detection module includes an open-circuit operating mode and a zero-voltage operating mode; wherein... The controllable power supply detection module is used to detect the voltage value between the first output terminal and the second output terminal through the third detection line and the fourth detection line in the open circuit operation mode; and to control the voltage between the first output terminal and the second output terminal to be 0 in the zero voltage operation mode, and to detect the current value flowing through the first output terminal and the second output terminal through the first detection line and the second detection line; in the open circuit operation mode, the first detection line and the second detection line are in a high resistance state, and the third detection line and the fourth detection line are also in a high resistance state.

9. The testing system according to claim 8, characterized in that, The circuit under test includes at least a driver module, an output module, and a matching module; The driving module is connected to the output module and is used to drive the output module; The output module includes a first output terminal and a second output terminal; The matching module is connected in series between the first output terminal and the second output terminal.

10. The testing system according to claim 9, characterized in that, The driving module includes a constant current source, which is connected to the output module and is used to provide a current driving signal. The output module includes two output units, and each output unit includes a first switching transistor and a second switching transistor. In the same output unit, the first terminal of the first switch is connected to the driving module, the second terminal of the first switch is connected to the second terminal of the second switch, the second terminal of the second switch is grounded, the control terminal of the first switch is used to receive a first control signal, and the control terminal of the second switch is used to receive a second control signal; wherein... The first end of the first detection line and the first end of the third detection line are respectively connected to the second end of the first switch in one of the output units, and the first end of the second detection line and the first end of the fourth detection line are respectively connected to the second end of the first switch in another output unit.

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