Power supply circuit of test machine, test machine and test method

Abstract

The invention discloses a power supply circuit of a test machine, the test machine and a test method, the power supply circuit comprises an input branch, an output branch, a current feedback loop and a voltage feedback loop, the input branch comprises a voltage conversion module, a current amplifier, a control bridge and a current input module; the voltage conversion module is used for converting a voltage digital quantity into a current signal and inputting the current signal into the current amplifier, the output end of the current amplifier is connected with the first end of the control bridge, and the two current input modules respectively output current to the second end and the third end of the control bridge; the input end of the output branch is connected with the fourth end of the control bridge, the output end is configured to be connected with the first end of a tested device, and the second end of the tested device is grounded; the input end and the output end of the current feedback loop are respectively connected with the output end and the input end of the output branch; and the voltage feedback loop obtains a feedback regulation result according to the real-time voltage of the tested device and inputs the feedback regulation result to the current amplifier. According to the invention, rapid switching of voltage and / or current can be realized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor testing, and in particular to a power supply circuit of a tester, a tester and a test method. Background Art

[0002] In the semiconductor industry, test equipment is usually divided into testers, test stations and sorters. The tester is mainly composed of some electronic circuit function boards, powered by a power supply, with communication power-on function, connected to the industrial computer upstream, and the test station downstream. The test station is mainly composed of a specific loop composed of electronic circuits, and has specific test functions. It is connected to the tester upstream to test the connected electronic components under test. The sorter classifies the test results (successful, failed, partial failure, etc.) according to the test results of the electronic components (voltage, current value, deviation, fluctuation, etc.). The sorter sends a start test signal to the test station, and the test station can only start the test after receiving the start test signal. After the test is completed, the test station will send the test results to the sorter, and the sorter will classify according to the test results.

[0003] In the prior art, a set of test machines is only responsible for powering the devices under test in a set of test stations. However, the sorting machine will have a lot of idle time when switching test stations, which will cause a waste of time resources. Therefore, letting a set of test machines be responsible for powering the devices under test in multiple sets of test stations (one machine for multiple uses) can maximize the use of test resources. However, the existing test machines lack a power supply circuit suitable for one machine for multiple uses. If the power supply object of the test machine is directly switched, the test machine cannot quickly switch to the voltage and / or current required by the current device under test, so that the voltage and / or current used by the previous device under test will affect the test of the current device under test, resulting in inaccurate test results of the device under test. Summary of the invention

[0004] The purpose of the present invention is to provide a power supply circuit of a tester, a tester and a test method, which can realize the multi-purpose use of the tester and ensure the accuracy of the test results of the device under test.

[0005] In order to achieve the above object, the present invention provides a power supply circuit of a test machine, which is used to supply power to a device under test in a test station, comprising: An input branch, the input branch comprises a voltage conversion module, a current amplifier, a control bridge and a current input module; the voltage conversion module is used to convert the input voltage digital quantity into a current signal and then input it into the current amplifier, the output end of the current amplifier is connected to the first end of the control bridge, the two current input modules respectively output current to the second end and the third end of the control bridge according to the input current digital quantity, by controlling the output current of the two current input modules, so that there is no pressure difference between the first end and the fourth end of the control bridge, and the fourth end of the control bridge outputs a voltage signal, or a pressure difference is generated between the first end and the fourth end of the control bridge, and the fourth end of the control bridge outputs a current signal; An output branch, the output branch is used to drive and amplify the input electrical signal and then output it, the input end of the output branch is connected to the fourth end of the control bridge, the output end of the output branch is configured to connect to the first end of the device under test, and the second end of the device under test is grounded; A current feedback loop, the current feedback loop is used to perform feedback regulation on the output of the output branch, the input end of the current feedback loop is connected to the output end of the output branch, and the output end of the current feedback loop is connected to the input end of the output branch; A voltage feedback loop is used to perform feedback regulation according to the real-time voltage of the device under test, and input the obtained feedback regulation result into the current amplifier.

[0006] Compared with the prior art, the present application controls the output of a current signal or a voltage signal through a control bridge, and the output branch drives and amplifies the output signal to the device under test, which can adapt to different test requirements of the device under test. When the control bridge controls the output current, the current feedback loop plays a major control role in the output of the output branch, and the voltage feedback loop performs feedback adjustment according to the real-time voltage at both ends of the device under test and outputs the obtained feedback adjustment result to the current amplifier to assist the adjustment of the current feedback loop; when the control bridge controls the output voltage, the voltage feedback loop plays a major control role in the output of the output branch, and the current feedback loop performs feedback adjustment according to the output of the output branch and outputs the feedback adjustment result to the input end of the output branch to assist the adjustment of the voltage feedback loop, thereby realizing the rapid switching of voltage and / or current, and preventing the test results from being inaccurate due to the current and / or voltage of the device under test failing to meet the test requirements in time.

[0007] Optionally, the control bridge comprises a first diode and a second diode connected in series, and a third diode and a fourth diode connected in series; The anode of the first diode is connected to the anode of the third diode, the cathode of the first diode is connected to the anode of the second diode, the cathode of the second diode is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; The node between the first diode and the second diode is the first end of the control bridge, the node between the first diode and the third diode is the second end of the control bridge, the node between the second diode and the fourth diode is the third end of the control bridge, and the node between the third diode and the fourth diode is the fourth end of the control bridge.

[0008] Optionally, the voltage feedback loop includes a high-end feedback branch and a low-end feedback branch; the input end of the high-end feedback branch is configured to be connected to the first end of the device under test, and the output end of the high-end feedback branch is connected to the input end of the current amplifier; the input end of the low-end feedback branch is configured to be connected to the second end of the device under test, and the output end of the low-end feedback branch is connected to the input end of the current amplifier.

[0009] Optionally, the high-end feedback branch includes a first buffer, a regulator and a high-end feedback resistor connected in series in sequence; the input end of the first buffer is configured to be connected to the first end of the device under test, the output end of the first buffer is connected to the input end of the regulator, the regulator is used to amplify or reduce the input voltage signal and output it to the first end of the high-end feedback resistor, and the second end of the high-end feedback resistor is connected to the input end of the current amplifier.

[0010] Optionally, the high-end feedback branch further includes a compensation resistor, a first end of the compensation resistor is connected to the input end of the regulator, and a second end of the compensation resistor is connected to the first end of the control bridge.

[0011] Optionally, the low-end feedback branch includes a second buffer and a low-end feedback resistor connected in series, the input end of the second buffer is configured to be connected to the second end of the device under test, the output end of the second buffer is connected to the first end of the low-end feedback resistor, and the second end of the low-end feedback resistor is connected to the input end of the current amplifier.

[0012] Optionally, the output branch includes a drive controller and a power amplifier, the current feedback loop includes a current feedback device, the input end of the drive controller is connected to the fourth end of the control bridge, the output end of the drive controller is connected to the input end of the power amplifier, the output end of the power amplifier is configured to be connected to the first end of the device under test and to the input end of the current feedback device, and the output end of the current feedback device is connected to the input end of the drive controller.

[0013] In order to achieve the above-mentioned purpose, the present application also discloses a testing machine, including a controller, a plurality of switches and the above-mentioned power supply circuit; each of the switches is configured to connect to one of the test stations, and the controller controls the opening and closing of the switches. When any of the switches is closed, the controller controls the voltage digital quantity input by the voltage conversion module and the current digital quantity input by the current input module through the corresponding test station, and the testing machine supplies power to the device under test of the corresponding test station through the power supply circuit.

[0014] Optionally, the test machine further comprises a voltage measurer and a current measurer, wherein the voltage measurer and the current measurer are respectively used to obtain the voltage and current of the device under test; A voltage measuring switch is connected between the controller and the voltage measuring device, and the current measuring switch is connected between the controller and the current measuring device. When the voltage measuring switch is closed, the voltage measuring device obtains the voltage of the device under test, and when the current measuring switch is closed, the current measuring device obtains the current of the device under test.

[0015] In order to achieve the above-mentioned purpose, the present application also discloses a test method for testing using the above-mentioned test machine, comprising a plurality of threads, wherein each of the test stations corresponds to one of the threads, each of the threads shares a thread lock, the thread lock is used to manage the resources of the test machine, so that each of the threads asynchronously uses the resources of the test machine, and for each of the threads, the step of powering the device under test comprises: Determine whether the thread lock can be locked; If yes, lock the thread lock, initialize the equipment of the test station, and load the resources of the test machine, wherein the resources of the test machine include the switch and the power supply circuit corresponding to the test station; Unlocking the thread lock; Determine whether the thread lock can be locked; If yes, lock the thread lock, and after receiving the test start signal sent by the sorting machine, use the allocated resources of the test machine to perform the test; After the test is completed, the resources of the test machine are released; Unlock the thread lock.

[0016] In the testing method of the present application, when one of the test machines has loaded the test resources, since it takes a certain amount of time for the sorting machine to switch test stations, this gap can be used to test the devices under test in the test station, thereby making full use of the idle time of the sorting machine when switching test stations and improving the testing efficiency of the testing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a circuit diagram of the power supply circuit of the test machine according to an embodiment of the present application.

[0018] Figure 2 This is a control schematic diagram of the controller of the test machine according to an embodiment of the present application.

[0019] Figure 3 Schematic diagram of the test method of the embodiment of the present application.

[0020] Figure 4 This is a schematic diagram of the relationship between the test machine and the test station in the embodiment of the present application.

[0021] Figure 5 This is a schematic diagram of the structure of the test equipment according to the embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0023] See also Figure 5 The test equipment involved in the present application includes a test machine 100, at least two test stations 200 and a sorting machine 300. Among them, the test machine 100 is responsible for supplying power to the device under test 201 in one of the test stations 200, the test station 200 is responsible for testing the device under test 201, and the sorting machine 300 is responsible for sorting each device under test 201 according to the test results of the test station 200. The sorting machine 300 can only sort the device under test 201 of one test station 200 at the same time. If it is to switch to another test station 200, it takes a certain amount of time to switch. The test machine 100 can only supply power to the device under test 201 in the test station 200 corresponding to the start test signal after receiving the start test signal (SOT, start of test) from the sorting machine 300.

[0024] See also Figure 4 For ease of understanding, the test machine 100 involved in this application can be regarded as a multimeter, the test station 200 can be regarded as the test leads of the multimeter, and the device under test 201 can be regarded as a resistor or other device. Of course, the above equivalence is only for the convenience of understanding the technical solution of this application and cannot be understood as a limitation of this application.

[0025] In the prior art, a set of test machines 100 is only responsible for supplying power to the devices under test 201 (such as diodes, triodes and MOSFET tubes, etc.) in a set of test stations 200. If a set of test machines 100 is to be responsible for supplying power to the devices under test 201 in multiple test stations 200 (one machine for multiple uses), it is not enough to simply switch the test machine 100 from one test station 200 to another test station 200. This is because the test products of different test stations 200 are different, and the test parameters (such as rated voltage and rated current) of different test products are not necessarily the same. In addition, electrical interference such as voltage, current and magnetic field will be generated inside the test machine 100. If the devices under test 201 in the test station 200 cannot quickly reach the voltage and / or current required for the test when switching the test station 200, the test effect will be inaccurate. Therefore, a power supply circuit 1 of the test machine 100 is required, so that the test machine 100 can achieve rapid switching of voltage and / or current when switching the test station 200.

[0026] For this, see Figure 1 The present application discloses a power supply circuit 1 of a test machine 100, which is used to supply power to a device under test 201 in a test station 200, including: Input branch 11, input branch 11 includes a voltage conversion module 111, a current amplifier 112, a control bridge 113, and a current input module 114; the voltage conversion module 111 is used to convert the input voltage digital quantity into a current signal and then input it into the current amplifier 112, the output end of the current amplifier 112 is connected to the first end of the control bridge 113, and the two current input modules 114 output current to the second end and the third end of the control bridge 113 according to the input current digital quantity. By controlling the output current of the two current input modules 114, there is no pressure difference between the first end and the fourth end of the control bridge 113, and the fourth end of the control bridge 113 outputs a voltage signal, or a pressure difference is generated between the first end and the fourth end of the control bridge 113, and the fourth end of the control bridge 113 outputs a current signal.

[0027] Output branch 12, output branch 12 is used to output a current signal or a voltage signal according to the output signal type of the control bridge 113, the input end of the output branch 12 is connected to the fourth end of the control bridge 113, the output end of the output branch 12 is configured to connect to the first end of the device under test 201, and the second end of the device under test 201 is grounded.

[0028] The current feedback loop 13 is used to drive and amplify the input electrical signal and then output it. The input end of the current feedback loop 13 is connected to the output end of the output branch 12, and the output end of the current feedback loop 13 is connected to the input end of the output branch 12.

[0029] The voltage feedback loop 14 is used to perform feedback regulation according to the real-time voltage of the device under test 201, and input the obtained feedback regulation result to the current amplifier 112. It can be understood that after the feedback regulation result is input to the current amplifier 112, the voltage and / or current of the first end of the control bridge 113 will be changed, thereby adjusting the output of the control bridge 113.

[0030] Compared with the prior art, the present application controls the output of a current signal or a voltage signal through the control bridge 113, and the output branch 12 drives and amplifies the output signal and outputs it to the device under test 201, which can adapt to different test requirements of the device under test 201. When the control bridge 113 controls the output current, the current feedback loop 13 controls the output of the output branch 12, and the voltage feedback loop 14 performs feedback adjustment according to the real-time voltage at both ends of the device under test 201 and outputs the obtained feedback adjustment result to the current amplifier 112 to assist the adjustment of the current feedback loop 13 (that is, the output of the voltage feedback loop 14 is clamped); when the control bridge 113 controls the output voltage, the voltage feedback loop 14 controls the output of the output branch 12, and the current feedback loop 13 performs feedback adjustment according to the output of the output branch 12 and outputs the obtained feedback adjustment result to the input end of the output branch 12 to assist the adjustment of the voltage feedback loop 14 (that is, the output of the current feedback loop 13 is clamped). Therefore, the present application can realize fast switching of voltage and / or current, and prevent inaccurate test results due to the voltage and / or current of the device under test 201 failing to meet the test requirements in time.

[0031] In some embodiments, the voltage conversion module 111 includes a voltage input module (not shown) and a voltage-current conversion module (not shown). The voltage input module is used to convert a voltage digital quantity into a voltage signal, and the voltage-current conversion module converts the voltage signal into a current signal and outputs it to the current amplifier 112.

[0032] See also Figure 1 In some embodiments, the control bridge 113 includes a first diode D1 and a second diode D2 connected in series, and a third diode D3 and a fourth diode D4 connected in series. The anode of the first diode D1 is connected to the anode of the third diode D3, the cathode of the first diode D1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the fourth diode D4, and the cathode of the third diode D3 is connected to the anode of the fourth diode D4. The node between the first diode D1 and the second diode D2 is the first end of the control bridge 113, the node between the first diode D1 and the third diode D3 is the second end of the control bridge 113, the node between the second diode D2 and the fourth diode D4 is the third end of the control bridge 113, and the node between the third diode D3 and the fourth diode D4 is the fourth end of the control bridge 113.

[0033] When the current can flow from the second end of the control bridge 113 through the first and fourth ends of the control bridge 113, and then flow from the first and fourth ends of the control bridge 113 to the third end of the control bridge 113, the voltages at the first and fourth ends of the control bridge 113 are the same, and the control bridge 113 outputs a voltage to the outside.

[0034] When the current flows from the second end of the control bridge 113 to the first end and the fourth end of the control bridge 113, but cannot flow from the first end and the fourth end of the control bridge 113 to the third end of the control bridge 113, the voltages of the first end and the fourth end of the control bridge 113 are different, and the control bridge 113 outputs current to the outside. Specifically, if the voltage between the two current input modules 114 is constant, the current flowing through the second end and the third end of the control bridge 113 is fixed. The current flowing through the second end of the control bridge 113 is divided into two paths to the first end of the control bridge 113 and the fourth end of the control bridge 113. Assuming that in this process, the voltage of the first end of the control bridge 113 is higher than the voltage of the fourth end of the control bridge 113, the current flowing through the fourth end of the control bridge 113 will be larger than the first end of the control bridge 113. Since the current flowing through the second end of the control bridge 113 is equal to the sum of the currents flowing through the first and fourth ends of the control bridge 113, the maximum current flowing through the fourth end of the control bridge 113 will not exceed the current flowing through the second end of the control bridge 113. If the maximum current cannot raise the voltage of the fourth end of the control bridge 113 to the same as the voltage of the first end of the control bridge 113, a voltage drop will be formed between the first and fourth ends of the control bridge 113, and the circuit will operate in current output.

[0035] See also Figure 1 In some embodiments, the voltage feedback loop 14 includes a high-end feedback branch 141 and a low-end feedback branch 142; the input end of the high-end feedback branch 141 is configured to be connected to the first end of the device under test 201, and the output end of the high-end feedback branch 141 is connected to the input end of the current amplifier 112; the input end of the low-end feedback branch 142 is configured to be connected to the second end of the device under test 201, and the output end of the low-end feedback branch 142 is connected to the input end of the current amplifier 112.

[0036] Specifically, the high-end feedback branch 141 includes a first buffer 1411, a regulator 1412 and a high-end feedback resistor R1 connected in series in sequence; the input end of the first buffer 1411 is configured to connect to the first end of the device under test 201, the output end of the first buffer 1411 is connected to the input end of the regulator 1412, the regulator 1412 is used to adjust the input voltage signal (amplify or reduce the voltage signal) and then output it to the first end of the high-end feedback resistor R1, and the second end of the high-end feedback resistor R1 is connected to the input end of the current amplifier 112.

[0037] Optionally, the high-end feedback branch 141 further includes a compensation resistor R2, a first end of the compensation resistor R2 is connected to the input end of the regulator 1412, and a second end of the compensation resistor R2 is connected to the first end of the control bridge 113. The test machine 100 (equivalent to a multimeter) includes a plurality of gear resistors, and different gears correspond to different gear resistors (not shown), and the compensation resistor R2 can compensate for the voltage division of the gear resistor, so that the output of the output branch 12 is more accurate.

[0038] Optionally, the first buffer 1411 is a voltage follower modified from an operational amplifier. Of course, it is not limited thereto. This is a technical means well known to those skilled in the art and will not be described in detail.

[0039] Specifically, the low-end feedback branch 142 includes a second buffer 1421 and a low-end feedback resistor R3 connected in series, the input end of the second buffer 1421 is configured to be connected to the second end of the device under test 201, the output end of the second buffer 1421 is connected to the first end of the low-end feedback resistor R3, and the second end of the low-end feedback resistor R3 is connected to the input end of the current amplifier 112.

[0040] Optionally, the second buffer 1421 is a voltage follower modified from an operational amplifier. Of course, it is not limited thereto. This is a technical means well known to those skilled in the art and will not be described in detail.

[0041] See also Figure 1 In some embodiments, the output branch 12 includes a drive controller 121 and a power amplifier 122, the current feedback loop 13 includes a current feedback device 131, the input end of the drive controller 121 is connected to the fourth end of the control bridge 113, the output end of the drive controller 121 is connected to the input end of the power amplifier 122, the output end of the power amplifier 122 is configured to connect to the first end of the device under test 201 and to the input end of the current feedback device 131, and the output end of the current feedback device 131 is connected to the input end of the drive controller 121. Among them, the power amplifier 122 requires additional drive, otherwise the output signal of the control bridge 113 alone cannot directly control the power amplifier 122, and the drive controller 121 is used to amplify and accelerate the input signal and then output it to the power amplifier 122, providing additional drive for the power amplifier 122.

[0042] Optionally, the output branch 12 is also connected in series to a resistor R4 including an output end of the power amplifier 122 , one end of the resistor R4 is connected to the power amplifier 122 , and the other end is configured to be connected to the device under test 201 and to be connected to an input end of the current feedback device 131 .

[0043] Optionally, the current feedback device 131 may be modified from an operational amplifier. Of course, this is not limited thereto. This is a technical means well known to those skilled in the art and will not be described in detail.

[0044] See also Figure 2 The present application also discloses a test machine 100, including a controller 2, a plurality of switches 3 and the above-mentioned power supply circuit 1; each switch 3 is configured to connect to a test station 200, and the controller 2 controls the opening and closing of the switch 3. When any switch 3 is closed, the controller 2 controls the voltage digital quantity input by the voltage conversion module and the current digital quantity input by the current input module through the corresponding test station 200, and the test machine 100 supplies power to the device under test 201 of the corresponding test station 200 through the power supply circuit 1.

[0045] Specifically, the corresponding voltage digital quantity and current digital quantity can be preset based on the working voltage / current of different test stations 200, so that when the switch 3 corresponding to a certain test station 200 is closed, the controller 2 can select the corresponding voltage digital quantity and current digital quantity. For example, the controller 2 can establish a corresponding relationship between the switch 3 and the digital quantity, and after controlling a certain switch to be closed 3, the corresponding digital quantity can be controlled to be input.

[0046] See also Figure 2 In some embodiments, the test machine 100 further includes a voltage measurer 4 and a current measurer 5 , and the voltage measurer 4 and the current measurer 5 are used to obtain the voltage and current of the device under test 201 , respectively.

[0047] Specifically, a voltage measurement switch 6 is connected between the controller 2 and the voltage measurement device 4, and a current measurement switch 7 is connected between the controller 2 and the current measurement device 5. When the voltage measurement switch 6 is closed, the voltage measurement device 4 obtains the voltage of the device under test 201, and when the current measurement switch 7 is closed, the current measurement device 5 obtains the current of the device under test 201.

[0048] Optionally, the switch 3 may be a relay, which is a technical means well known to those skilled in the art and will not be described in detail.

[0049] The sorting machine 300 will have a lot of idle time when switching the test station 200, which will cause a waste of time resources. If the devices in the test station 200 can be tested during this interval, the work efficiency can be greatly improved.

[0050] See also Figure 3 In this regard, the present application also discloses a test method using the above-mentioned test machine 100 for testing, including a plurality of threads, wherein each test station 200 corresponds to a thread, each thread shares a thread lock, and the thread lock is used to manage the resources of the test machine so that each thread uses the resources of the test machine asynchronously. For each thread, the step of supplying power to the device under test 201 includes: S1, determine whether the thread lock can be locked.

[0051] S2, if yes, lock the thread lock, initialize the equipment of the test station 200, and load the resources of the test machine 100. The resources of the test machine 100 include the switch 3 and the power supply circuit 1 corresponding to the test station 200.

[0052] S3, unlocks the thread lock.

[0053] S4, determine whether the thread lock can be locked.

[0054] S5, if yes, the thread lock is locked, and after receiving the start test signal sent by the sorting machine 300, the test is performed using the allocated test machine 100 resources. It can be understood that when the sorting machine 300 switches from other test stations 200 to the test station 200 corresponding to the current thread, it will send a start test signal to the thread, so that the thread can be tested when the sorting machine 300 switches the test station 200.

[0055] S6, after the test is completed, the resources of the test machine 100 are released.

[0056] S7, unlocks the thread lock.

[0057] See also Figure 3 For ease of understanding, take two threads (thread A and thread B) as an example. After thread A executes steps S1-S3, it releases the thread lock, and thread B, which also has the test requirement, obtains the thread lock, so that thread B can also execute steps S1-S3. At this time, both thread A and thread B are ready for testing. Then thread A continues to obtain the thread lock and executes steps S4-S7. After thread A executes step S7, the resources of the test machine 100 are in an idle state, and thread B obtains the thread lock and can also execute steps S4-S7. In this way, the test method can make full use of the idle time of the sorting machine 300 when switching the test station 200, thereby improving the test efficiency of the test equipment.

[0058] In some embodiments, in step S7, after unlocking the thread lock, the process further includes: S8, repeating steps S4-S7 to repeat the test steps. It can be understood that if the resources of the test machine 100 have been released at this time, the resources of the test machine 100 are loaded before the test is performed using the allocated resources of the test machine 100.

[0059] Optionally, the number of threads is 2. In practice, when the number of circuits is large, electrical interferences such as voltage, current, and magnetic field will be generated, which will affect the test results, especially in the test machine 100, such as milli (mA, mV) and micro (μA, μV) of small gears. When the number of threads is 2, the resource utilization rate is greater, the circuit formed by the test machine 100 and the test station 200 is more convenient to control, and the test data of electronic components is more accurate.

[0060] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A power supply circuit of a test machine, used to supply power to a device under test in a test station, characterized in that: include: An input branch, the input branch comprising a voltage conversion module, a current amplifier, a control bridge and a current input module; The voltage conversion module is used to convert the input voltage digital quantity into a current signal and then input it into the current amplifier. The output end of the current amplifier is connected to the first end of the control bridge. The two current input modules output current to the second end and the third end of the control bridge respectively according to the input current digital quantity. By controlling the output current of the two current input modules, there is no pressure difference between the first end and the fourth end of the control bridge, and the fourth end of the control bridge outputs a voltage signal, or a pressure difference is generated between the first end and the fourth end of the control bridge, and the fourth end of the control bridge outputs a current signal; An output branch, the output branch is used to drive and amplify the input electrical signal and then output it, the input end of the output branch is connected to the fourth end of the control bridge, the output end of the output branch is configured to connect to the first end of the device under test, and the second end of the device under test is grounded; A current feedback loop, the current feedback loop is used to perform feedback regulation on the output of the output branch, the input end of the current feedback loop is connected to the output end of the output branch, and the output end of the current feedback loop is connected to the input end of the output branch; A voltage feedback loop is used to perform feedback regulation according to the real-time voltage of the device under test, and input the obtained feedback regulation result into the current amplifier.

2. The power supply circuit according to claim 1, characterized in that: The control bridge comprises a first diode and a second diode connected in series, and a third diode and a fourth diode connected in series; The anode of the first diode is connected to the anode of the third diode, the cathode of the first diode is connected to the anode of the second diode, the cathode of the second diode is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; The node between the first diode and the second diode is the first end of the control bridge, the node between the first diode and the third diode is the second end of the control bridge, the node between the second diode and the fourth diode is the third end of the control bridge, and the node between the third diode and the fourth diode is the fourth end of the control bridge.

3. The power supply circuit according to claim 1, characterized in that: The voltage feedback loop includes a high-end feedback branch and a low-end feedback branch; the input end of the high-end feedback branch is configured to be connected to the first end of the device under test, and the output end of the high-end feedback branch is connected to the input end of the current amplifier; the input end of the low-end feedback branch is configured to be connected to the second end of the device under test, and the output end of the low-end feedback branch is connected to the input end of the current amplifier.

4. The power supply circuit according to claim 3, characterized in that: The high-end feedback branch includes a first buffer, a regulator and a high-end feedback resistor connected in series in sequence; the input end of the first buffer is configured to be connected to the first end of the device under test, the output end of the first buffer is connected to the input end of the regulator, the regulator is used to amplify or reduce the input voltage signal and output it to the first end of the high-end feedback resistor, and the second end of the high-end feedback resistor is connected to the input end of the current amplifier.

5. The power supply circuit according to claim 4, characterized in that: The high-end feedback branch further includes a compensation resistor, a first end of the compensation resistor is connected to the input end of the regulator, and a second end of the compensation resistor is connected to the first end of the control bridge.

6. The power supply circuit according to claim 3, characterized in that: The low-end feedback branch includes a second buffer and a low-end feedback resistor connected in series, the input end of the second buffer is configured to be connected to the second end of the device under test, the output end of the second buffer is connected to the first end of the low-end feedback resistor, and the second end of the low-end feedback resistor is connected to the input end of the current amplifier.

7. The power supply circuit according to claim 1, characterized in that: The output branch includes a drive controller and a power amplifier, the current feedback loop includes a current feedback device, the input end of the drive controller is connected to the fourth end of the control bridge, the output end of the drive controller is connected to the input end of the power amplifier, the output end of the power amplifier is configured to be connected to the first end of the device under test and to the input end of the current feedback device, and the output end of the current feedback device is connected to the input end of the drive controller.

8. A testing machine, characterized in that: It comprises a controller, a plurality of switches and a power supply circuit as described in any one of claims 1 to 7; each of the switches is configured to connect to a test station, the controller controls the opening and closing of the switches, and when any of the switches is closed, the controller controls the voltage digital quantity input by the voltage conversion module and the current digital quantity input by the current input module through the corresponding test station, and the test machine supplies power to the device under test of the corresponding test station through the power supply circuit.

9. The testing machine according to claim 1, characterized in that: The test machine further includes a voltage measurer and a current measurer, wherein the voltage measurer and the current measurer are used to obtain the voltage and current of the device under test respectively; A voltage measuring switch is connected between the controller and the voltage measuring device, and the current measuring switch is connected between the controller and the current measuring device. When the voltage measuring switch is closed, the voltage measuring device obtains the voltage of the device under test, and when the current measuring switch is closed, the current measuring device obtains the current of the device under test.

10. A testing method using the testing machine as claimed in claim 9, characterized in that: The method comprises a plurality of threads, wherein each of the test stations corresponds to one of the threads, and each of the threads shares a thread lock, and the thread lock is used to manage the resources of the test machine so that each of the threads asynchronously uses the resources of the test machine. For each of the threads, the step of supplying power to the device under test comprises: Determine whether the thread lock can be locked; If yes, lock the thread lock, initialize the equipment of the test station, and load the resources of the test machine, wherein the resources of the test machine include the switch and the power supply circuit corresponding to the test station; Unlocking the thread lock; Determine whether the thread lock can be locked; If yes, lock the thread lock, and after receiving the test start signal sent by the sorting machine, use the allocated resources of the test machine to perform the test; After the test is completed, the resources of the test machine are released; Unlock the thread lock.

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