Testing device for evaluating operational amplifier chip parameters

Abstract

A testing device for evaluating operational amplifier chip parameters comprises a power supply unit, a main control unit, an adjusting unit and an auxiliary unit, and the power supply unit is electrically connected with the main control unit, the adjusting unit and the auxiliary unit. The main control unit comprises a single chip microcomputer, and two control output ends of the single chip microcomputer are correspondingly connected with two control input ends of the adjusting unit and the auxiliary unit respectively; the adjusting unit comprises an analog switch and test resistors R4-R7 which are sequentially connected in series and have different resistance values, the analog switch is a four-channel analog switch, the two ends of the R4 are electrically connected with the output pins X1 and X2 of the analog switch respectively, the two ends of the R5 are electrically connected with the output pins X0 and X1 respectively, the two ends of the R6 are electrically connected with the output pins X0 and X3 respectively, and the other end of the R7 is grounded; an input pin X of the analog switch is connected with an inverted input end of the chip to be tested; the auxiliary unit comprises an analog switch and four light emitting diodes. The device is high in test automation degree, high in test precision, low in cost, high in reliability and free of a mechanical action switch, and mechanical loss is avoided.

Description

Technical Field

[0001] This utility model relates to a testing device, and more particularly to a testing device for evaluating chip parameters. Background Technology

[0002] Currently, operational amplifiers are installed in various systems in the military product field to form module circuits for signal amplification, filtering, voltage-to-current conversion and other signal processing. The demand for domestically produced chips is increasing, and understanding the capabilities of domestically produced chips is of paramount importance.

[0003] Currently, characteristic curves are crucial references for chip parameters in chip capabilities, relating to other parameters under different gains. Unused chips in semiconductor integrated circuits require application verification. For operational amplifiers, several curves are plotted to correlate gain with certain parameters, such as the curve of input voltage frequency versus gain. This testing currently employs a purely manual method: soldering different feedback resistors to create circuits with different gains (e.g., 1, 10, 100, 1000), and measuring different gain curves under the influence of different input frequencies. This process is repeated by switching to another gain factor to obtain the relevant curves. This method is inefficient and cannot meet the requirements.

[0004] The above manual testing operation has the following problems in actual practice:

[0005] 1. Traditional imported programmable switchgear is expensive, resulting in a waste of resources;

[0006] 2. Frequent replacement of the feedback network resistor during gain switching increases the error rate of human operation, such as incorrect resistor value replacement or poor soldering.

[0007] 3. Repeated soldering will introduce some errors, affecting the test accuracy; moreover, repeated soldering processes may cause the solder pads to fall off, thus requiring the replacement of the test board, making it impossible to maintain the test rules under the same conditions, resulting in inaccurate test data.

[0008] 4. Multiple soldering operations will require a longer time. For test devices that need to be tested under high and low temperature conditions, a longer time means temperature recovery, which can lead to inaccurate tests. Utility Model Content

[0009] The technical problem to be solved by this utility model is to provide a test device for evaluating operational amplifier chip parameters with automated testing and high testing accuracy.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A test device for evaluating the parameters of operational amplifier chips includes a power supply unit, a main control unit, an adjustment unit, and an auxiliary unit. The power output terminal of the power supply unit is electrically connected to the main control unit, the adjustment unit, and the auxiliary unit, respectively, to provide working power to each unit.

[0012] The main control unit includes a microcontroller, whose two control output terminals are respectively connected to the two control input terminals of the adjustment unit and the auxiliary unit, and are used to control the corresponding channel switching operations in the adjustment unit and the auxiliary unit.

[0013] The adjustment unit includes an analog switch and test resistors R4 to R7 connected in series with different resistance values. The analog switch is a four-channel analog switch. The two ends of the test resistor R4 are electrically connected to the output pins X1 and X2 of the analog switch, respectively. The two ends of the test resistor R5 are electrically connected to the output pins X0 and X1 of the analog switch, respectively. The two ends of the test resistor R6 are electrically connected to the output pins X0 and X3 of the analog switch, respectively. The other end of the test resistor R7 is grounded. The input pin X of the analog switch is connected to the inverting input terminal of the chip under test, which is used to control the connection of different resistors to the circuit to switch the gain.

[0014] The auxiliary unit includes an analog switch and four light-emitting diodes. The input pin of the analog switch is connected to the power output terminal of the power supply unit through a pull-up resistor R1, and the four output pins are each connected to a light-emitting diode for observing the switching gain level.

[0015] As a further preferred embodiment, the main control unit is also equipped with a DIP switch, which is also connected to two control input terminals of the adjustment unit and the auxiliary unit, for manually controlling the corresponding channel switching operation in the adjustment unit and the auxiliary unit.

[0016] As a further preferred embodiment, the microcontroller is an STC15W408AS microcontroller, wherein port P1.2 is used as the AD acquisition voltage and is used to connect to the E3631 power supply; ports P3.6 and P3.7 are the control output terminals and are used to connect to the control input terminals of the adjustment unit.

[0017] As a further preferred embodiment, the adjustment unit and the auxiliary unit share a single RS2252 analog switch and each uses one of the four channels of the analog switch to simplify the structure.

[0018] As a further preferred embodiment, the power supply unit includes a reverse connection protection circuit consisting of a MOSFET, a light-emitting diode, a capacitor C5, and two resistors R13 and R14; used to connect a DC power supply to power the main control unit, the adjustment unit, and the auxiliary unit.

[0019] As a further preferred option, the MOS transistor is an AO3401 PMOS transistor.

[0020] The beneficial effects of this utility model are:

[0021] 1. Since the main control unit uses a microcontroller to control the corresponding channel switching in the adjustment unit and auxiliary unit, the adjustment unit can switch the gain by connecting different resistors to the circuit through the control of the main control unit. The test has a high degree of automation and high accuracy, low cost, high reliability, and no mechanical action switches, thus avoiding mechanical wear.

[0022] 2. The addition of a DIP switch to the main control unit facilitates manual debugging and verification, ensuring the accuracy of automatic testing; the analog switch of the adjustment unit controlled by the microcontroller is more convenient, and the auxiliary unit settings facilitate the identification of faults and faster problem detection. Attached Figure Description

[0023] Figure 1 This is the circuit block diagram of this utility model.

[0024] Figure 2 This is the circuit diagram of the power supply unit.

[0025] Figure 3 This is the circuit schematic of the main control unit.

[0026] Figure 4 This is the circuit schematic of the adjustment unit.

[0027] Figure 5 This is the circuit schematic of the auxiliary unit.

[0028] Figure 6 This is the circuit schematic diagram of this utility model. Detailed Implementation

[0029] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0030] like Figures 1-6 As shown, this utility model relates to a test device for evaluating the parameters of operational amplifier chips, which includes a power supply unit, a main control unit, an adjustment unit, and an auxiliary unit. The power output terminal of the power supply unit is electrically connected to the main control unit, the adjustment unit, and the auxiliary unit, respectively, to provide working power to each unit.

[0031] The power supply unit includes a reverse polarity protection circuit consisting of a MOSFET Q3, a light-emitting diode LED5, a capacitor C5, and two resistors R13 and R14 connected together; it is used to connect a DC power supply to provide +5V power to the main control unit, adjustment unit, and auxiliary unit. The MOSFET is an AO3401 PMOS transistor.

[0032] The main control unit includes a microcontroller U3 and a DIP switch SW1. The microcontroller is an STC15W408AS microcontroller, where P1.2 is used as an AD acquisition port to connect to the output of the E3631 DC power supply; P3.6 and P3.7 are two control output terminals A and B, which output either a high level or a low level. The two control output terminals are respectively connected to the two control input terminals of the adjustment unit and the auxiliary unit to control the corresponding channel switching operation in the adjustment unit and the auxiliary unit.

[0033] The DIP switch is an SW-DIP2, whose two input terminals are connected to the power output terminals of the power supply unit through pull-up resistors R12 and R11, respectively. The control output terminals are also connected to the two control input terminals of the adjustment unit and the auxiliary unit, respectively, for manually controlling the corresponding channel switching in the adjustment unit and the auxiliary unit. The two output terminals of the DIP switch are grounded simultaneously.

[0034] The adjustment unit includes an analog switch U2 and test resistors R4 to R7 connected in series with different resistance values. The analog switch U2 is a four-channel analog switch. The control pins A and B of the analog switch U2 are the two control input terminals of the adjustment unit. The two ends of the test resistor R4 are electrically connected to the output pins X1 and X2 of the analog switch U2, respectively. The two ends of the test resistor R5 are electrically connected to the output pins X0 and X1 of the analog switch U2, respectively. The two ends of the test resistor R6 are electrically connected to the output pins X0 and X3 of the analog switch U2, respectively. The other end of the test resistor R7 is grounded. The input pin X of the analog switch is electrically connected to the inverting input terminal of the chip under test U1, which is used to control the connection of different resistors to the circuit to switch the gain.

[0035] The auxiliary unit includes an analog switch U2 and four light-emitting diodes (LEDs) LED1 to LED4. The input pin Y of the analog switch U2 is connected to the power output of the power supply unit via a pull-up resistor R1. The four output pins Y0 to Y3 are connected one-to-one with LEDs LED1 to LED4. The other ends of LEDs LED1 to LED4 are grounded, allowing observation of the gain level. The adjustment unit and the auxiliary unit share a single RS2252 analog switch and each uses one of the four channels of the analog switch U2 to simplify the structure.

[0036] During testing, if Figure 6As shown, taking the GQFOP07 chip under test (DUT) U1 as an example, the non-inverting input terminal of DUT U1 is connected to a sine wave signal, for example, with a frequency of 10kHz and an amplitude of 1V, through resistor R2 and interface CON2. The output terminal of DUT U1 is connected to the upper end of test resistor R4 through resistor R3 and then connected to an oscilloscope through interface CON1, forming a non-inverting amplifier. The voltage acquired by the P1.2 port of the microcontroller controls the output of ports P3.7 and P3.6 to be high or low. At this time, all DIP switches SW1 are in the off state, and the output is as follows:

[0037] When the voltage sampled from port P1.2 is 1.2V, BA = 00;

[0038] When the voltage sampled from port P1.2 is 1.3V, BA = 01;

[0039] When the voltage sampled from port P1.2 is 1.4V, BA = 10;

[0040] When the voltage collected by port P1.2 is 1.5V, BA = 11.

[0041] When the control output terminal BA of the microcontroller U3 is 00, the gain is 1 + (R4 + R5) / (R6 + R7) = 100, and the LED1 of the auxiliary unit lights up through the analog switch U2 connected to the +5V power supply. When the control output terminal BA is 01, the gain is 1 + R4 / (R6 + R7 + R5) = 10, and the LED2 of the auxiliary unit lights up through the analog switch U2. When the control output terminal BA is 10, the gain is 1 + 0 / (R4 + R5 + R6 + R7) = 1, and the LED3 of the auxiliary unit lights up through the analog switch U2. When the control output terminal BA is 11, the gain is 1 + (R4 + R5 + R6) / (R7) = 1000, and the LED4 of the auxiliary unit lights up through the analog switch U2. Therefore, the selected gain can be determined by which LED is lit. By connecting an oscilloscope, you can check whether the output signal of the chip under test U1 is attenuated under different gains.

[0042] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A test device for evaluating the parameters of operational amplifier chips, comprising a power supply unit, a main control unit, an adjustment unit, and an auxiliary unit, wherein the power output terminal of the power supply unit is electrically connected to the main control unit, the adjustment unit, and the auxiliary unit respectively, for providing working power to each unit; The main control unit includes a microcontroller, whose two control output terminals are respectively connected to the two control input terminals of the adjustment unit and the auxiliary unit, and are used to control the corresponding channel switching operations in the adjustment unit and the auxiliary unit. The adjustment unit includes an analog switch and test resistors R4 to R7 connected in series with different resistance values. The analog switch is a four-channel analog switch. The two ends of the test resistor R4 are electrically connected to the output pins X1 and X2 of the analog switch, respectively. The two ends of the test resistor R5 are electrically connected to the output pins X0 and X1 of the analog switch, respectively. The two ends of the test resistor R6 are electrically connected to the output pins X0 and X3 of the analog switch, respectively. The other end of the test resistor R7 is grounded. The input pin X of the analog switch is connected to the inverting input terminal of the chip under test, which is used to control the connection of different resistors to the circuit to switch the gain. The auxiliary unit includes an analog switch and four light-emitting diodes. The input pin of the analog switch is connected to the power output terminal of the power supply unit through a pull-up resistor R1, and the four output pins are each connected to a light-emitting diode for observing the switching gain level.

2. The testing apparatus for evaluating operational amplifier chip parameters according to claim 1, characterized in that: The main control unit is also equipped with a DIP switch, which is connected to two control input terminals of the adjustment unit and the auxiliary unit, and is used to manually control the corresponding channel switching in the adjustment unit and the auxiliary unit.

3. The testing apparatus for evaluating operational amplifier chip parameters according to claim 1, characterized in that: The microcontroller used is an STC15W408AS microcontroller, where P1.2 is used as the AD acquisition voltage and is connected to the E3631 power supply; P3.6 and P3.7 are the control output terminals and are used to connect to the control input terminals of the adjustment unit.

4. The testing apparatus for evaluating operational amplifier chip parameters according to claim 1, characterized in that: The adjustment unit and the auxiliary unit share an RS2252 analog switch and each uses one of the four channels of the analog switch to simplify the structure.

5. The testing apparatus for evaluating operational amplifier chip parameters according to claim 1, characterized in that: The power supply unit includes a reverse connection protection circuit consisting of a MOSFET, a light-emitting diode, a capacitor C5, and two resistors R13 and R14; it is used to connect a DC power supply to power the main control unit, the adjustment unit, and the auxiliary unit.

6. The test apparatus for evaluating operational amplifier chip parameters according to claim 5, characterized in that: The MOS transistor is an AO3401 PMOS transistor.

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