Light emitting diode tester

Abstract

The utility model relates to a light emitting diode tester, comprising a control unit; the input end of the digital-to-analog conversion unit is connected with the output end of the control unit; the output of the digital-to-analog conversion unit is connected with the input of the voltage-to-current conversion unit; the feedback unit comprises a current feedback unit and a voltage feedback unit, and the input of the current feedback unit and the input of the voltage feedback unit are respectively connected with the output of the voltage-current conversion unit; the output of the current feedback unit and the output of the voltage feedback unit are respectively connected with the control unit through an analog-to-digital conversion unit, and the output of the voltage feedback unit is also connected with the input of the voltage-current conversion unit through a clamping voltage unit; and the output unit is connected with the output of the voltage and current conversion unit. According to the invention, the light emitting diode can be conveniently tested in a constant-voltage and constant-current mode.

Description

Technical Field

[0001] The present disclosure belongs to the field of electronic test instruments, and particularly relates to a light-emitting diode tester. Background Art

[0002] In the ex-factory quality control stage of light-emitting diodes (LEDs), it is generally necessary to sample a certain proportion of LEDs, and a test instrument is required to drive the LEDs during the sampling process. There are generally two ways to drive LEDs, namely constant current drive and constant voltage drive, that is, controlling the drive current and collecting the voltage across the LED (constant current) and controlling the drive voltage and collecting the current flowing through the LED (constant voltage). By comparing the voltage and current data, it is determined whether the function of the LED meets the ex-factory requirements. The existing light-emitting diode test devices have insufficient output voltage and current stability and insufficient test accuracy for light-emitting diodes. Summary of the Utility Model

[0003] The present utility model provides a light-emitting diode tester, aiming to solve at least one of the technical problems existing in the prior art.

[0004] The technical solution of the present utility model is a light-emitting diode tester, including:

[0005] A control unit;

[0006] A digital-to-analog conversion unit, the input end of the digital-to-analog conversion unit is connected to the output end of the control unit;

[0007] A voltage-current conversion unit, the output of the digital-to-analog conversion unit is connected to the input of the voltage-current conversion unit;

[0008] A feedback unit, the feedback unit includes a current feedback unit and a voltage feedback unit, the inputs of the current feedback unit and the voltage feedback unit are respectively connected to the output of the voltage-current conversion unit, the outputs of the current feedback unit and the voltage feedback unit are respectively connected to the control unit through an analog-to-digital conversion unit, and the output of the voltage feedback unit is also connected to the input of the voltage-current conversion unit through a clamping voltage unit;

[0009] An output unit, the output unit is connected to the output of the voltage-current conversion unit.

[0010] Further, it further includes a current buffer unit and a voltage buffer unit, the input ends of the current buffer unit and the voltage buffer unit are respectively connected to the output end of the digital-to-analog conversion unit, and the output ends of the current buffer unit and the voltage buffer unit are respectively connected to the input end of the voltage-current conversion unit.

[0011] Further, the input end of the clamping voltage unit is connected to the output of the voltage buffer unit, and the output end of the clamping voltage unit is connected to the input end of the voltage-current conversion unit.

[0012] Further, the control unit is a ZYNQ controller, the digital-to-analog conversion unit is an AD5752RBREZ, the digital-to-analog conversion unit includes an I_SET terminal connected to the current buffer unit and a V_SET terminal connected to the voltage buffer unit, the I_SET terminal is connected to the digital-to-analog conversion unit through the VOUTA terminal, and the V_SET terminal is connected to the digital-to-analog conversion unit through the VOUTB terminal.

[0013] Further, the voltage-current conversion unit includes a second resistor, a first five-capacitor, a 3-A operational amplifier, a 4-A operational amplifier, a fourth resistor, a fourth seven-resistor, a sixty-first resistor, a sixty-second resistor, a sixty-fourth resistor, a forty-fourth resistor, a third resistor, a sixty-third resistor, a fifth resistor, a forty-fifth resistor, a 25-A operational amplifier, a thirty-nine resistor, a thirty-eight resistor, a fortieth diode, a sixth resistor, a thirty-nine capacitor, a forty-second resistor, a forty-third resistor, an eighth resistor, a first triode, a nineteenth capacitor, a 5-A operational amplifier, a second diode, a twentieth capacitor, a one-hundred-and-fourteenth resistor, a tenth resistor, a ninety-eighth resistor, a 38-A operational amplifier, a ninety-third capacitor, a nineteenth diode, a ninety-ninth resistor, a 7-A operational amplifier, a twelfth resistor, a fifteenth resistor, a thirteenth resistor, a fourteenth resistor, a fortieth resistor, a forty-first resistor, and a forty-first capacitor;

[0014] The I_SET terminal is connected to the non-inverting input terminal of the 3-A operational amplifier through the second resistor, the second terminal of the second resistor is connected to the inverting input terminal of the 3-A operational amplifier and the analog ground through the first five-capacitor, the output terminal of the 3-A operational amplifier is sequentially connected to the inverting input terminal of the 25-A operational amplifier through the fourth resistor, the fourth seven-resistor, the sixty-first resistor, the sixty-second resistor, the fifth resistor, and the forty-fifth resistor, the inverting input terminal of the 25-A operational amplifier is connected to the second terminal of the sixty-second resistor through the forty-fourth resistor, the two RG ports of the 25-A operational amplifier are connected through the third resistor R3, the sixty-fourth resistor, and the sixty-third resistor, the output terminal of the 25-A operational amplifier is sequentially connected to the reference voltage input terminal of the 25-A operational amplifier and the analog ground through the thirty-nine resistor, the fortieth capacitor, and the thirty-eight resistor, the non-inverting input terminal of the 4-A operational amplifier is grounded through the sixth resistor and the thirty-nine capacitor, the non-inverting input terminal of the 4-A operational amplifier is connected to the second terminal of the fifth resistor through the sixth resistor, and the inverting input terminal of the 4-A operational amplifier is connected to the output terminal and then connected to the reference voltage terminal of the 3-A operational amplifier.

[0015] Further, the V_SET end is connected to the non-inverting input terminal of the 5-A operational amplifier through an eighth resistor. The second terminal of the eighth resistor is connected to the analog ground through a nineteenth capacitor. The inverting input terminal of the 5-A operational amplifier is connected to the collector of the first triode. The base of the first triode is connected to the output terminal of the 3-A operational amplifier through a forty-third resistor. The emitter of the first triode is connected to the output terminal of the 5-A operational amplifier and the third terminal of the second diode. The first terminal of the second diode is connected to the second terminal of the fourth resistor through a forty-second resistor. The output terminal of the 5-A operational amplifier is grounded through a twentieth capacitor and a one-hundred-and-fourteenth resistor in sequence. The first terminal of the one-hundred-and-fourteenth resistor is connected to the output terminal of the 7-A operational amplifier through a tenth resistor.

[0016] Further, the second terminal of the tenth resistor is connected to the inverting input terminal of the 38-A operational amplifier through a ninety-eighth resistor. The non-inverting input terminal of the 38-A operational amplifier is grounded. The inverting input terminal of the 38-A operational amplifier is connected to the output terminal of the 38-A operational amplifier through a ninety-third capacitor. The output terminal of the 38-A operational amplifier is grounded through a nineteenth diode, a ninety-ninth resistor and a thirty-ninth diode in sequence. The first terminal of the nineteenth diode is connected to the output terminal of the 7-A operational amplifier through a ninety-eighth resistor;

[0017] The non-inverting input terminal of the 7-A operational amplifier is connected to the SMU_OUT+ output terminal through a twelfth resistor and a fifteenth resistor R15 in sequence. The inverting input terminal of the 7-A operational amplifier is connected to the AGND_SMU terminal through a thirteenth resistor and a fourteenth resistor in sequence. The output terminal of the 7-A operational amplifier is connected to the SMU_VM+ terminal through a fortieth resistor. The reference voltage terminal of the 7-A operational amplifier is connected to the SMU_VM- terminal through a forty-first resistor.

[0018] Further, the analog-to-digital conversion unit includes an ADC_DOUTA port and an ADC_DOUTB port connected to the control unit. The ADC_DOUTA port is used to transmit the analog voltage quantity of the current feedback unit to the control unit. The ADC_DOUTB port is used to transmit the analog voltage quantity of the voltage feedback unit to the control unit.

[0019] Further, it further includes a host computer unit, and the host computer unit is connected to the control unit.

[0020] Further, it further includes a power supply unit, and the control unit, the digital-to-analog conversion unit, the feedback unit, the analog-to-digital conversion unit and the clamping voltage unit are respectively connected to the power supply unit.

[0021] The beneficial effects of the present utility model are as follows.

[0022] In this application, the light-emitting diode tester includes two output modes: constant current and constant voltage. The constant current mode can synchronously measure the voltage across the channel, and the constant voltage mode can synchronously measure the output current. The signal type and amplitude are adjustable. ZYNQ7020 is used as the main controller to control the DAC output and ADC data acquisition. The tester communicates with the host computer through Ethernet. This application can conveniently test the light-emitting diode in constant voltage and constant current modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic circuit block diagram of the light-emitting diode tester of the present utility model.

[0024] Figure 2 It is a schematic diagram of the test wiring method of the light-emitting diode tester of the present utility model.

[0025] Figure 3 It is a circuit diagram of the digital-to-analog conversion unit of the light-emitting diode tester of the present utility model.

[0026] Figure 4 It is a circuit diagram of the voltage-current conversion unit of the light-emitting diode tester of the present utility model.

[0027] Figure 5 It is a circuit diagram of the analog-to-digital conversion unit of the light-emitting diode tester of the present utility model.

[0028] Figure 6 It is a circuit diagram of the power supply unit of the light-emitting diode tester of the present utility model.

[0029] In the above figures, 100 is the control unit; 200 is the digital-to-analog conversion unit; 210 is the current buffer unit; 220 is the voltage buffer unit; 300 is the voltage-current conversion unit; 400 is the current feedback unit; 500 is the voltage feedback unit; 600 is the analog-to-digital conversion unit; 700 is the clamping voltage unit; 800 is the output unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following will clearly and completely describe the concept, specific structure and technical effects generated by the present utility model in combination with the embodiments and the drawings, so as to fully understand the purpose, solution and effects of the present utility model. It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0031] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. In addition, the descriptions such as up, down, left, right, top, bottom, etc. used in the present utility model are only relative to the mutual positional relationship of the various components of the present utility model in the drawings.

[0032] In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of this technology. The terms used in the description of this specification are only for describing specific embodiments, rather than for limiting the present utility model. The term "and / or" used herein includes any combination of one or more of the related listed items.

[0033] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of this disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0034] Referring to Figures 1 to 6 , in this application, a light-emitting diode tester is proposed. Referring to Figure 1 , it includes:

[0035] A control unit 100;

[0036] A digital-to-analog conversion unit 200, the input end of the digital-to-analog conversion unit 200 is connected to the output end of the control unit 100;

[0037] A voltage-current conversion unit 300, the output of the digital-to-analog conversion unit 200 is connected to the input of the voltage-current conversion unit 300;

[0038] A feedback unit, the feedback unit includes a current feedback unit 400 and a voltage feedback unit 500. The inputs of the current feedback unit 400 and the voltage feedback unit 500 are respectively connected to the output of the voltage-current conversion unit 300. The outputs of the current feedback unit 400 and the voltage feedback unit 500 are respectively connected to the control unit 100 through an analog-to-digital conversion unit 600. The output of the voltage feedback unit 500 is also connected to the input of the voltage-current conversion unit 300 through a clamping voltage unit 700;

[0039] An output unit 800, the output unit 800 is connected to the output of the voltage-current conversion unit 300.

[0040] The beneficial effects of the present utility model are as follows.

[0041] In this application, the light-emitting diode tester includes two output modes: constant current and constant voltage. In the constant current mode, the voltage across both ends of the channel can be synchronously measured, and in the constant voltage mode, the output current can be synchronously measured. The signal type and amplitude are adjustable. ZYNQ7020 is used as the main controller to control the DAC output and ADC data acquisition. The tester communicates with the host computer via Ethernet. This application can conveniently test the light-emitting diode in the constant voltage and constant current modes. The source measurement unit (SMU) can accurately initiate the simultaneous measurement of voltage and current. It integrates a digital multimeter (DMM), a voltage source, a current source, and a pulse generator compactly in one module. Due to the versatility and high-precision performance of the measuring instrument, in specific fields, the SMU has more advantages than any combination of several of these four instruments.

[0042] Specifically, referring to Figure 1 , the light-emitting diode tester selects DAC and ADC both with two channels, where:

[0043] Constant current output mode:

[0044] The ZYNQ controller controls the DAC to output a voltage signal, which is converted into a current signal through a voltage-current conversion circuit, and the output current is detected through a series resistor.

[0045] Constant voltage output mode:

[0046] The ZYNQ controller controls the DAC to output a voltage signal, which is converted into a current signal through a voltage-current conversion circuit. The voltage drop generated by the current signal on a 1k resistor is used to provide an external voltage. At the same time, this voltage is collected by the voltage feedback circuit. One path is used for the detection of the ADC to obtain the output voltage value, and the other path is used for negative feedback to the voltage-current conversion circuit to stabilize the output voltage.

[0047] In addition, since the constant voltage mode is achieved by controlling the current on the load, the constant voltage mode and the constant current mode cannot work simultaneously.

[0048] Referring to Figure 2 , connect the light-emitting diode under test to the IOut or V Out of the tester. Send a drive command through the PC terminal of the host computer to drive the light-emitting diode, and then send a collection command through the PC terminal. The tester will feedback the voltage or current value back to the PC terminal to complete the test function.

[0049] Furthermore, referring to Figure 1It further includes a current buffer unit 210 and a voltage buffer unit 220. The input ends of the current buffer unit 210 and the voltage buffer unit 220 are respectively connected to the output end of the digital-to-analog conversion unit 200, and the output ends of the current buffer unit 210 and the voltage buffer unit 220 are respectively connected to the input ends of the voltage-current conversion unit 300.

[0050] Further, referring to Figure 1 The input end of the clamping voltage unit 700 is connected to the output of the voltage buffer unit 220, and the output end of the clamping voltage unit 700 is connected to the input end of the voltage-current conversion unit 300.

[0051] Further, referring to Figure 1 The control unit 100 is a ZYNQ controller, and the digital-to-analog conversion unit 200 is an AD5752RBREZ. The digital-to-analog conversion unit 200 includes an I_SET end connected to the current buffer unit 210 and a V_SET end connected to the voltage buffer unit 220. The I_SET end is connected to the digital-to-analog conversion unit 200 through the VOUTA end, and the V_SET end is connected to the digital-to-analog conversion unit 200 through the VOUTB end.

[0052] Further, referring to Figure 4 The voltage-current conversion unit 300 includes a second resistor R2, a first five-capacitor C15, a 3-A operational amplifier U3-A, a 4-A operational amplifier U4-A, a fourth resistor R4, a fourth seven-resistor R47, a sixth one-resistor R61, a sixth two-resistor R62, a sixth four-resistor R64, a fourth four-resistor R44, a third resistor R3, a sixth three-resistor R63, a fifth resistor R5, a fourth five-resistor R45, a 25-A operational amplifier U25-A, a third nine-resistor R39, a third eight-resistor R38, a fourth zero-diode D4, a sixth resistor R6, a third nine-capacitor C39, a fourth two-resistor R42, a fourth three-resistor R43, an eighth resistor R8, a first triode Q1, a first nine-capacitor C19, a 5-A operational amplifier U5-A, a second diode D2, a second zero-capacitor C20, a first one four-resistor R114, a first zero-resistor R10, a ninety-eight resistor R98, a 38-A operational amplifier U38-A, a ninety-three capacitor C93, a first nine-diode D19, a ninety-nine resistor R99, a 7-A operational amplifier U7-A, a first two-resistor R12, a first five-resistor R15, a first three-resistor R13, a first four-resistor R14, a fourth zero-resistor R40, a fourth one-resistor R41, and a fourth one-capacitor C41;

[0053] The I_SET terminal is connected to the non-inverting input terminal of the 3-A operational amplifier U3-A through the second resistor R2. The second terminal of the second resistor R2 is connected to the inverting input terminal of the 3-A operational amplifier U3-A and analog ground through the first five-capacitor C15. The output terminal of the 3-A operational amplifier U3-A is sequentially connected to the inverting input terminal of the 25-A operational amplifier U25-A through the fourth resistor R4, the forty-seventh resistor R47, the sixty-first resistor R61, the sixty-second resistor R62, the fifth resistor R5, and the forty-fifth resistor R45. The inverting input terminal of the 25-A operational amplifier U25-A is connected to the second terminal of the sixty-second resistor R62 through the forty-fourth resistor R44. The two RG ports of the 25-A operational amplifier U25-A are connected through the third resistor R3, the sixty-fourth resistor R64, and the sixty-third resistor R63. The output terminal of the 25-A operational amplifier U25-A is sequentially connected to the reference voltage input terminal of the 25-A operational amplifier U25-A and analog ground through the thirty-ninth resistor R39, the fortieth capacitor, and the thirty-eighth resistor R38. The non-inverting input terminal of the 4-A operational amplifier U4-A is grounded through the sixth resistor R6 and the thirty-ninth capacitor C39. The non-inverting input terminal of the 4-A operational amplifier U4-A is connected to the second terminal of the fifth resistor R5 through the sixth resistor R6. The inverting input terminal of the 4-A operational amplifier U4-A is connected to the output terminal and then connected to the reference voltage terminal of the 3-A operational amplifier U3-A.

[0054] Further, referring to Figure 4 , the V_SET terminal is connected to the non-inverting input terminal of the 5-A operational amplifier U5-A through the eighth resistor R8. The second terminal of the eighth resistor R8 is connected to analog ground through the nineteenth capacitor C19. The inverting input terminal of the 5-A operational amplifier U5-A is connected to the collector of the first triode Q1. The base of the first triode Q1 is connected to the output terminal of the 3-A operational amplifier U3-A through the forty-third resistor R43. The emitter of the first triode Q1 is connected to the output terminal of the 5-A operational amplifier U5-A and the third terminal of the second diode D2. The first terminal of the second diode D2 is connected to the second terminal of the fourth resistor R4 through the forty-second resistor R42. The output terminal of the 5-A operational amplifier U5-A is sequentially grounded through the twentieth capacitor C20 and the one hundred and fourteenth resistor R114. The first terminal of the one hundred and fourteenth resistor R114 is connected to the output terminal of the 7-A operational amplifier U7-A.

[0055] Further, referring to Figure 4, the second end of the first zero-resistance R10 is connected to the inverting input terminal of the 38-A operational amplifier U38-A through the ninety-eighth resistor R98. The non-inverting input terminal of the 38-A operational amplifier U38-A is grounded. The inverting input terminal of the 38-A operational amplifier U38-A is connected to the output terminal of the 38-A operational amplifier U38-A through the ninety-third capacitor C93. The output terminal of the 38-A operational amplifier U38-A is grounded successively through the nineteenth diode D19, the ninety-ninth resistor R99, and the thirty-ninth diode. The first end of the nineteenth diode D19 is connected to the output terminal of the 7-A operational amplifier U7-A through the ninety-eighth resistor R98;

[0056] The non-inverting input terminal of the 7-A operational amplifier U7-A is connected to the SMU_OUT+ output terminal successively through the twelfth resistor R12 and the fifteenth resistor R15. The inverting input terminal of the 7-A operational amplifier U7-A is connected to the AGND_SMU terminal successively through the thirteenth resistor R13 and the fourteenth resistor R14. The output terminal of the 7-A operational amplifier U7-A is connected to the SMU_VM+ terminal through the fortieth resistor R40. The reference voltage terminal of the 7-A operational amplifier U7-A is connected to the SMU_VM- terminal through the forty-first resistor R41.

[0057] Further, referring to Figure 5 , the analog-to-digital conversion unit 600 includes an ADC_DOUTA port and an ADC_DOUTB port connected to the control unit 100. The ADC_DOUTA port is used to transmit the analog voltage of the current feedback unit 400 to the control unit 100, and the ADC_DOUTB port is used to transmit the analog voltage of the voltage feedback unit 500 to the control unit 100.

[0058] Further, it further includes a host computer unit, and the host computer unit is connected to the control unit 100.

[0059] In some specific embodiments, the host computer unit is connected to the control unit 100 through a serial port or a network.

[0060] Further, referring to Figure 6 , it further includes a power supply unit, and the control unit 100, the digital-to-analog conversion unit 200, the feedback unit, the analog-to-digital conversion unit 600, and the clamping voltage unit 700 are respectively connected to the power supply unit.

[0061] The following are typical application examples of the light-emitting diode tester:

[0062] (1) 30 mA constant current DC drive

[0063] Load: 100Ω, current value: 30mA, voltage value: 4V (in constant current drive mode, the set voltage value should be: voltage value > load * current value)

[0064] >smu_output(SMU,1)

[0065] >smu_mode(SMU,0)

[0066] >smu_set(SMU,volt=4V,curr=30mA) / / Given a load of 100Ω and a current of 30mA, the voltage across the DUT is 3V. To ensure a 30mA current can pass through the DUT, volt should be greater than 3V, so volt is set to 4V

[0067] >pulse_config(SMU,pw=1000us,period=1500us,repect=1,capturedelay=500us,prestore=10us)

[0068] / / Only limit the measurement function, sample the signal within 500μs (capturedelay) - 1000μs (pw)

[0069] >pulse_start(SMU,7)

[0070] >smu_get_average(SMU)

[0071] Even when the module is working in constant current mode, it is necessary to call >pulse_config because this instruction is not only used to set the pulse waveform for the output function but also used to limit the sampling delay and sampling time for the measurement function. Therefore, as long as the measurement function is required, >pulse_config needs to be set.

[0072] (2) 30mA constant current pulse drive

[0073] Load: 100Ω, current value: 30mA, voltage value: 5V (in constant current drive mode, the set voltage value should be: voltage value > load * current value), pulse width: 1000μs, period: 2000μs

[0074] >smu_output(SMU,1)

[0075] >smu_mode(SMU,1)

[0076] >pulse_config(SMU,pw = 1000us,period = 2000us,repect = 10,capturedelay = 500us,prestore = 10us)

[0077] / / Define the pulse signal waveform and measurement function, pulse width 1000μs, period 2000μs, pulse repetition 10 times, and sample the voltage and current within 500μs (capturedelay) - 1000μs (pw) of the pulse signal

[0078] >smu_set(SMU,volt = 5V,curr = 30mA)

[0079] >pulse_start(SMU,7)

[0080] >smu_get_average(SMU)

[0081] (3) 2.5V constant voltage DC drive

[0082] Load 100Ω, current value 50mA (in constant voltage drive mode, the current value should be set as: voltage value < load * current value), voltage value 2.5V

[0083] >smu_output(SMU,1)

[0084] >smu_mode(SMU,0)

[0085] >smu_set(SMU,volt = 2.5V,curr = 50mA) / / From the load of 100Ω and voltage of 2.5V, the current is 25mA. To ensure the voltage remains constant at 2.5V, curr should be greater than 25mA, so curr = 50mA is set

[0086] >pulse_config(SMU,pw = 1000us,period = 1500us,repect = 1,capturedelay = 500us,prestore = 10us)

[0087] / / Only define the measurement function and sample the signal within 500μs (capturedelay) - 1000μs (pw)

[0088] >pulse_start(SMU,7)

[0089] >smu_get_average(SMU)

[0090] (4) 2.5V constant voltage pulse drive

[0091] The load is 100 Ω, the current value is 50 mA (in the constant voltage drive mode, the current value should be set as: voltage value < load * current value), the voltage value is 2.5 V, the pulse width is 1000 μs, and the period is 2000 μs.

[0092] >smu_output(SMU,1)

[0093] >smu_mode(SMU,1)

[0094] >pulse_config(SMU,pw=1000us,period=2000us,repect=1,capturedelay=500us,prestore=10us)

[0095] / / Define the pulse signal waveform and measurement function, with a pulse width of 1000 μs, a period of 2000 μs, 1 pulse repetition, and sample the voltage and current within 500 μs (capturedelay) - 1000 μs (pw) of the pulse signal.

[0096] >smu_set(SMU,volt=2.5V,curr=50mA)

[0097] >pulse_start(SMU,7)

[0098] >smu_get_average(SMU)

[0099] The above are only the preferred embodiments of the present invention. The present invention is not limited to the above embodiments. As long as it achieves the technical effects of the present invention by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure should be included within the scope of protection of the present disclosure. All should belong to the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation manners can have various different modifications and changes.

Claims

1. A light-emitting diode tester, characterized in that, Comprising: A control unit (100); A digital-to-analog conversion unit (200), the input end of the digital-to-analog conversion unit (200) being connected to the output end of the control unit (100); A voltage-current conversion unit (300), the output of the digital-to-analog conversion unit (200) being connected to the input of the voltage-current conversion unit (300); A feedback unit, the feedback unit comprising a current feedback unit (400) and a voltage feedback unit (500), the inputs of the current feedback unit (400) and the voltage feedback unit (500) being respectively connected to the output of the voltage-current conversion unit (300), the outputs of the current feedback unit (400) and the voltage feedback unit (500) being respectively connected to the control unit (100) through an analog-to-digital conversion unit (600), and the output of the voltage feedback unit (500) being further connected to the input of the voltage-current conversion unit (300) through a clamping voltage unit (700); An output unit (800), the output unit (800) being connected to the output of the voltage-current conversion unit (300).

2. The light-emitting diode tester according to claim 1, wherein It further comprises a current buffer unit (210) and a voltage buffer unit (220), the input ends of the current buffer unit (210) and the voltage buffer unit (220) being respectively connected to the output end of the digital-to-analog conversion unit (200), and the output ends of the current buffer unit (210) and the voltage buffer unit (220) being respectively connected to the input end of the voltage-current conversion unit (300).

3. The light-emitting diode tester according to claim 2, wherein The input end of the clamping voltage unit (700) is connected to the output of the voltage buffer unit (220), and the output end of the clamping voltage unit (700) is connected to the input end of the voltage-current conversion unit (300).

4. The light-emitting diode tester according to claim 2, wherein The control unit (100) is a ZYNQ controller, the digital-to-analog conversion unit (200) is an AD5752RBREZ, the digital-to-analog conversion unit (200) comprises an I_SET end connected to the current buffer unit (210) and a V_SET end connected to the voltage buffer unit (220), the I_SET end is connected to the digital-to-analog conversion unit (200) through the VOUTA end, and the V_SET end is connected to the digital-to-analog conversion unit (200) through the VOUTB end.

5. The light-emitting diode tester according to claim 4, wherein The voltage-current conversion unit (300) includes a second resistor (R2), a first five-capacitor (C15), a 3-A operational amplifier (U3-A), a 4-A operational amplifier (U4-A), a fourth resistor (R4), a fourth seven-resistor (R47), a sixty-first resistor (R61), a sixty-second resistor (R62), a sixty-fourth resistor (R64), a forty-fourth resistor (R44), a third resistor (R3), a sixty-third resistor (R63), a fifth resistor (R5), a forty-fifth resistor (R45), a 25-A operational amplifier (U25-A), a thirty-ninth resistor (R39), a thirty-eighth resistor (R38), a fortieth diode (D4), a sixth resistor (R6), a thirty-ninth capacitor (C39), a forty-second resistor (R42), a forty-third resistor (R43), an eighth resistor (R8), a first triode (Q1), a nineteenth capacitor (C19), a 5-A operational amplifier (U5-A), a second diode (D2), a twentieth capacitor (C20), a one-hundred-and-fourteenth resistor (R114), a tenth resistor (R10), a ninety-eighth resistor (R98), a 38-A operational amplifier (U38-A), a ninety-third capacitor (C93), a nineteenth diode (D19), a ninety-ninth resistor (R99), a 7-A operational amplifier (U7-A), a twelfth resistor (R12), a fifteenth resistor (R15), a thirteenth resistor (R13), a fourteenth resistor (R14), a fortieth resistor (R40), a forty-first resistor (R41), and a forty-first capacitor (C41); The I_SET terminal is connected to the non-inverting input terminal of the 3-A operational amplifier (U3-A) through the second resistor (R2). The second terminal of the second resistor (R2) is connected to the inverting input terminal of the 3-A operational amplifier (U3-A) and analog ground through the first five-capacitor (C15). The output terminal of the 3-A operational amplifier (U3-A) is sequentially connected to the inverting input terminal of the 25-A operational amplifier (U25-A) through the fourth resistor (R4), the forty-seventh resistor (R47), the sixty-first resistor (R61), the sixty-second resistor (R62), the fifth resistor (R5), and the forty-fifth resistor (R45). The inverting input terminal of the 25-A operational amplifier (U25-A) is connected to the second terminal of the sixty-second resistor (R62) through the forty-fourth resistor (R44). The two RG ports of the 25-A operational amplifier (U25-A) are connected through the third resistor (R3), the sixty-fourth resistor (R64), and the sixty-third resistor (R63). The output terminal of the 25-A operational amplifier (U25-A) is sequentially connected to the reference voltage input terminal of the 25-A operational amplifier (U25-A) and analog ground through the thirty-ninth resistor (R39), the fortieth capacitor (C40), and the thirty-eighth resistor (R38). The non-inverting input terminal of the 4-A operational amplifier (U4-A) is grounded through the sixth resistor (R6) and the thirty-ninth capacitor (C39). The non-inverting input terminal of the 4-A operational amplifier (U4-A) is connected to the second terminal of the fifth resistor (R5) through the sixth resistor (R6). The inverting input terminal of the 4-A operational amplifier (U4-A) is connected to the output terminal and then connected to the reference voltage terminal of the 3-A operational amplifier (U3-A).

6. The light-emitting diode tester according to claim 5, wherein The V_SET terminal is connected to the non-inverting input terminal of the 5-A operational amplifier (U5-A) through the eighth resistor R8. The second terminal of the eighth resistor (R8) is connected to analog ground through the nineteenth capacitor (C19). The inverting input terminal of the 5-A operational amplifier (U5-A) is connected to the collector of the first triode (Q1). The base of the first triode (Q1) is connected to the output terminal of the 3-A operational amplifier (U3-A) through the forty-third resistor (R43). The emitter of the first triode (Q1) is connected to the output terminal of the 5-A operational amplifier (U5-A) and the third terminal of the second diode (D2). The first terminal of the second diode (D2) is connected to the second terminal of the fourth resistor (R4) through the forty-second resistor (R42). The output terminal of the 5-A operational amplifier (U5-A) is sequentially grounded through the twentieth capacitor (C20) and the one hundred and fourteenth resistor (R114). The first terminal of the one hundred and fourteenth resistor (R114) is connected to the output terminal of the 7-A operational amplifier (U7-A) through the tenth resistor (R10).

7. The light emitting diode tester according to claim 6, wherein the second end of the first zero resistance (R10) is connected to the inverting input terminal of the 38-A operational amplifier (U38-A) through the ninety-eighth resistance (R98), the non-inverting input terminal of the 38-A operational amplifier (U38-A) is grounded, the inverting input terminal of the 38-A operational amplifier (U38-A) is connected to the output terminal of the 38-A operational amplifier (U38-A) through the ninety-third capacitor (C93), the output terminal of the 38-A operational amplifier (U38-A) is grounded successively through the nineteenth diode (D19), the ninety-ninth resistance (R99) and the thirty-ninth diode (D39), and the first end of the nineteenth diode (D19) is connected to the output terminal of the 7-A operational amplifier (U7-A) through the ninety-eighth resistance (R98); the non-inverting input terminal of the 7-A operational amplifier (U7-A) is connected to the SMU_OUT+ output terminal successively through the twelfth resistance (R12) and the fifteenth resistance (R15), the inverting input terminal of the 7-A operational amplifier (U7-A) is connected to the AGND_SMU terminal successively through the thirteenth resistance (R13) and the fourteenth resistance (R14), the output terminal of the 7-A operational amplifier (U7-A) is connected to the SMU_VM+ terminal through the fortieth resistance (R40), and the reference voltage terminal of the 7-A operational amplifier (U7-A) is connected to the SMU_VM- terminal through the forty-first resistance (R41).

8. The light emitting diode tester according to claim 1, wherein the analog-to-digital conversion unit (600) includes an ADC_DOUTA port and an ADC_DOUTB port connected to the control unit (100). The ADC_DOUTA port is used to transmit the analog voltage of the current feedback unit (400) to the control unit (100), and the ADC_DOUTB port is used to transmit the analog voltage of the voltage feedback unit (500) to the control unit (100).

9. The light emitting diode tester according to claim 1, wherein it further includes a host computer unit, and the host computer unit is connected to the control unit (100).

10. The light emitting diode tester according to claim 1, wherein it further includes a power supply unit, and the control unit (100), the digital-to-analog conversion unit (200), the feedback unit, the analog-to-digital conversion unit (600) and the clamping voltage unit (700) are respectively connected to the power supply unit.

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