Small-size wide-range electronic load circuit

By designing a small-volume and wide-range electronic load circuit, the automatic testing of positive and negative power supplies and a wide current range are realized, which solves the problem of large volume and low integration of the board-level electronic load, improves the integration and reduces the cost.

CN223217651UActive Publication Date: 2025-08-12SUZHOU INTELLIGENT AUTOMATION EQUIP CO LTD
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Patent Information

Application Number
CN202422374608.2
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-09-27
Publication Date
2025-08-12
Estimated Expiration
2034-09-27

AI Technical Summary

Technical Problem

The existing electronic loads of the board-level card cannot perform current sinking tests on negative power supplies. They are large in size, low in integration, narrow current range and expensive instrument-level loads.

Method used

A small-volume wide-range electronic load circuit is designed, including electronic load boards and adapter boards. It adopts MCU main control, sampling module, op amp module and power module, which can automatically check the polarity of the power supply and conduct pull-up or sink current tests through automatic shifting function. The power device is placed outside the board and has a higher degree of integration.

Benefits of technology

Automatic testing of positive and negative power supplies is achieved, with a wide current range, small size and high integration, which solves the defects in the prior art.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to the technical field of electronic load, in particular to a small-size wide-range electronic load circuit, which comprises an electronic load board card and an adaptive board card, the electronic load board card is provided with a sampling module and an operational amplifier module connected with the sampling module, and the adaptive board card is provided with an MCU master controller, a power module and a protection module. The MCU master controller is connected with the operational amplifier module, the power module and the protection module. According to the board card level resistance load scheme, the positive electrode and the negative electrode of a power supply can be automatically checked, a pull current test is carried out on the positive power supply, a sink current test is carried out on the negative power supply, an automatic gear shifting function is adopted in the system, different current ranges are set, a power device is placed on a board card except an electronic load board card, and the test efficiency is improved. The size is reduced, and the integration level is higher.
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Description

Technical Field

[0001] The utility model relates to the technical field of electronic loads, in particular to a small-volume and wide-range electronic load circuit. Background Art

[0002] With the rapid development of electronic technology, the complexity and diversity of systems are increasing, and the integration of electronic products is becoming higher and higher, and the functionality is becoming more and more powerful. This puts higher requirements on the integration and functionality of electronic loads used in PCBA performance testing and calibration platforms for consumer electronic products.

[0003] A board-level electronic load is a device that absorbs and consumes electrical energy through electronic components. Unlike traditional resistive loads, electronic loads consume energy by controlling the conduction of internal power devices and relying on the power dissipation of power tubes. This design makes electronic loads more flexible and precise in regulation and control, and can simulate various load conditions such as steady-state, transient, short-circuit, and overcurrent, thereby meeting the needs of various applications such as power supply testing and electronic equipment debugging.

[0004] However, existing board-level electronic loads have the following defects:

[0005] 1. The board-level electronic load can only perform current sourcing test on the positive power supply, but cannot perform current sinking test on the negative power supply;

[0006] 2. The board-level electronic load contains power devices, which are relatively large and have low integration.

[0007] 3. The current range set by the board-level electronic load is relatively narrow;

[0008] 4. Instrument-grade electronic loads are expensive and bulky, making them unsuitable for highly integrated solutions.

[0009] In order to eliminate the above-mentioned defects of the board-level electronic load, a small-volume, wide-range electronic load circuit is proposed. Utility Model Content

[0010] The purpose of the present utility model is to provide a small-volume, wide-range electronic load circuit to solve the problems raised in the above-mentioned background technology.

[0011] To achieve the above objectives, the present invention provides a small-volume, wide-range electronic load circuit, comprising an electronic load board and an adapter board. The electronic load board is provided with a sampling module and an operational amplifier module connected to the sampling module. The adapter board is provided with an MCU main control, a power module, and a protection module. The MCU main control is connected to the operational amplifier module, the power module, and the protection module.

[0012] The MCU main control controls the power module to source current or sink current according to the positive and negative values of the collected voltage, and controls the gear of the source current or sink current through the sampling module and the operational amplifier module.

[0013] As a further improvement of the present technical solution, the sampling module includes a first sampling group and a second sampling group, the operational amplifier module includes operational amplifiers U3, U4, U5, and U6, and the power module includes MOS tubes Q1 and Q2, wherein:

[0014] The drain of the MOS tube Q1 is connected to the positive power supply terminal and to the ADC2 pin of the MCU main control, the source of the MOS tube Q1 is connected to the first sampling group and to the positive terminal of the operational amplifier U3, the first sampling group is connected to the negative terminal of the operational amplifier U3 and to ground, the operational amplifier U3 is connected to the negative terminal of the operational amplifier U4 and to the ADC5 pin of the MCU main control, the positive terminal of the operational amplifier U4 is connected to the DAC1 pin of the MCU main control, and the operational amplifier U4 is connected to the gate of the MOS tube Q1;

[0015] The drain of the MOS tube Q2 is connected to the negative power supply terminal and to the ADC4 pin of the MCU main control, the source of the MOS tube Q2 is connected to the second sampling group and to the positive terminal of the operational amplifier U5, the second sampling group is connected to the negative terminal of the operational amplifier U5 and to ground, the operational amplifier U5 is connected to the negative terminal of the operational amplifier U6 and to the ADC6 pin of the MCU main control, the positive terminal of the operational amplifier U6 is connected to the DAC2 pin of the MCU main control, and the operational amplifier U6 is connected to the gate of the MOS tube Q2.

[0016] As a further improvement of the present technical solution, the first sampling group and the second sampling group each include a plurality of sampling resistors with different resistance values.

[0017] The source of the MOS transistor Q1 is connected to the multiple sampling resistors of the first sampling group, and the source of the MOS transistor Q2 is connected to the multiple sampling resistors of the second sampling group;

[0018] Each sampling resistor in the first sampling group is connected to the negative terminal of the operational amplifier U3 through a single connected switch element, and each sampling resistor in the second sampling group is connected to the negative terminal of the operational amplifier U5 through a single connected switch element.

[0019] As a further improvement of the present technical solution, the protection module includes a dual protection circuit that cuts off the current output when the circuit temperature is too high or the voltage is too high, and the dual protection circuit is connected to the MCU main control.

[0020] As a further improvement of the technical solution, the dual protection circuit includes thermistors NTC1, NTC2, operational amplifiers U1, U2,

[0021] One end of the thermistor NTC1 is connected to the positive terminal of the operational amplifier U1 and connected to the 3V3 terminal through a 1k ohm resistor, and the other end of the thermistor NTC1 is grounded;

[0022] One end of the thermistor NTC2 is connected to the positive terminal of the operational amplifier U2 and connected to the 3V3 terminal through a 1k ohm resistor, and the other end of the thermistor NTC1 is grounded;

[0023] The operational amplifier U1 is connected to the ADC1 pin of the MCU main controller, and the operational amplifier U2 is connected to the ADC3 pin of the MCU main controller.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This small, wide-range electronic load circuit can automatically check the positive and negative poles of the power supply, perform current sourcing tests on the positive power supply, and current sinking tests on the negative power supply. The system uses an automatic shifting function to set different current ranges and places power devices on a board separate from the electronic load board, reducing its size and increasing its integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the overall structural diagram of the utility model;

[0027] Figure 2 This is the overall circuit diagram of the utility model. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0030] See also Figure 1-Figure 2As shown, this embodiment provides a small-volume, wide-range electronic load circuit, including an electronic load board and an adapter board. The electronic load board is provided with a sampling module and an operational amplifier module connected to the sampling module. The adapter board is provided with an MCU main control, a power module, and a protection module. The MCU main control is connected to the operational amplifier module, the power module, and the protection module.

[0031] The MCU main control collects the voltage value on the power supply through the ADC2 and ADC4 pins, automatically collects the positive voltage or negative voltage, which is the positive power supply source current or the negative power supply sink current, and starts the source current and sink current. The collected positive voltage corresponds to the positive power supply source current, and the collected negative voltage corresponds to the negative power supply sink current.

[0032] The MCU main control controls the power module to source or sink current according to the positive and negative values of the collected voltage, and controls the gear of source or sink current through the sampling module and operational amplifier module.

[0033] The sampling module includes a first sampling group and a second sampling group, the operational amplifier module includes operational amplifiers U3, U4, U5, and U6, and the power module includes MOS tubes Q1 and Q2, wherein:

[0034] The drain of MOS tube Q1 is connected to the positive power supply terminal and to the ADC2 pin of the MCU main controller. The source of MOS tube Q1 is connected to the first sampling group and to the positive terminal of operational amplifier U3. The first sampling group is connected to the negative terminal of operational amplifier U3 and to ground. Operational amplifier U3 is connected to the negative terminal of operational amplifier U4 and to the ADC5 pin of the MCU main controller. The positive terminal of operational amplifier U4 is connected to the DAC1 pin of the MCU main controller. Operational amplifier U4 is connected to the gate of MOS tube Q1.

[0035] The operational amplifier U3 collects the voltage on the sampling resistor. The collected voltage divided by the sampling resistor is equal to the current on the sampling resistor, which is the current pulled up by the electronic load. It is compared with the positive phase DAC1 pin of the operational amplifier U4, and the output controls the MOS tube Q1 and controls different current pull-up gears. The value of the positive power supply pull-up current is collected by the ADC5 pin. When the value is too large, the DAC1 pin can be controlled to turn off the MOS tube Q1 to turn off the current output. The positive phase of the operational amplifier U4 is the voltage value of the input DAC1, and the negative phase is the output voltage value of the operational amplifier U3, that is, the voltage on the sampling resistor is collected and output to control the MOS tube Q1, so that the positive phase and negative phase voltages of the operational amplifier U4 are the same, that is, the value of DAC1 is the same as the voltage value of the sampling resistor. The voltage value of the sampling resistor, that is, the current pulled up by the electronic load, can be controlled by DAC1.

[0036] The drain of MOS tube Q2 is connected to the negative power supply terminal and to the ADC4 pin of the MCU main controller. The source of MOS tube Q2 is connected to the second sampling group and to the positive terminal of operational amplifier U5. The second sampling group is connected to the negative terminal of operational amplifier U5 and to ground. Operational amplifier U5 is connected to the negative terminal of operational amplifier U6 and to the ADC6 pin of the MCU main controller. The positive terminal of operational amplifier U6 is connected to the DAC2 pin of the MCU main controller. Operational amplifier U6 is connected to the gate of MOS tube Q2.

[0037] The operational amplifier U5 collects the voltage on the sampling resistor and compares it with the positive phase DAC2 pin of the operational amplifier U6. The output controls the MOS tube Q2 and controls different current sinking gears. The value of the negative power supply current is collected by the ADC6 pin. When the value is too large, the DAC2 pin can be controlled to turn off the MOS tube Q2 to turn off the current output. The operational amplifier U5 mainly collects the voltage on the sampling resistor. The voltage can be collected through ADC6. The collected voltage divided by the sampling resistor is equal to the current on the sampling resistor, which is the current pulled up by the electronic load. The positive phase of the operational amplifier U6 is the voltage value of the input DAC2, and the negative phase is the output voltage value of the operational amplifier U5, that is, the voltage on the sampling resistor. The output controls the MOS tube Q2 so that the positive phase and negative phase voltages of the operational amplifier U6 are the same, that is, the value of DAC2 is the same as the voltage value of the sampling resistor. The voltage value of the sampling resistor can be controlled by DAC2.

[0038] The first sampling group and the second sampling group both include multiple sampling resistors with different resistance values, which can adapt to different current ranges. The 2K resistance resistor can adapt to the current of 0.5uA-100uA, the 10R resistance resistor can adapt to the current of 100uA-10mA, the 0.1R resistance resistor can adapt to the current of 10mA-1A, and the 0.01R resistance resistor can adapt to the current of 10A. The sampling resistors are switched by the MCU.

[0039] In this embodiment, the MCU automatically controls the output of a wide current range of 0.5uA-10A:

[0040] 0.5uA-100uA corresponds to a 20K sampling resistor, and the voltage on the sampling resistor is 10mV-2000mV;

[0041] 100uA-10mA corresponds to a 10R sampling resistor, and the voltage on the sampling resistor is 1mV-100mV;

[0042] 10mA-1A corresponds to a 0.1R sampling resistor, and the voltage on the sampling resistor is 1mV-100mV;

[0043] 1A-10A corresponds to a 0.01R sampling resistor, and the voltage on the sampling resistor is 10mV-100mV;

[0044] Different sampling resistors correspond to different voltage ranges. The voltage on the sampling resistor is compared with the positive-phase DAC1 of the operational amplifier U4, and the output controls the MOS tube Q1, and controls different current pull positions. The positive-phase DAC1 of the operational amplifier U4 has the same voltage as the sampling resistor. The voltage of ADC1 divided by the sampling voltage value equals the current.

[0045] Different sampling resistors correspond to different voltage ranges. The voltage on the sampling resistor is compared with the positive-phase DAC2 of the operational amplifier U6, and the output controls the MOS tube Q2, and controls different current sinking gears. The positive-phase DAC2 of the operational amplifier U6 has the same voltage as the sampling resistor. The voltage of ADC2 divided by the sampling voltage value is equal to the current.

[0046] The source of the MOS transistor Q1 is connected to the multiple sampling resistors of the first sampling group, and the source of the MOS transistor Q2 is connected to the multiple sampling resistors of the second sampling group;

[0047] Each sampling resistor in the first sampling group is connected to the negative terminal of the operational amplifier U3 through a single connected switch element, and each sampling resistor in the second sampling group is connected to the negative terminal of the operational amplifier U5 through a single connected switch element.

[0048] The protection module includes a dual protection circuit that cuts off the current output when the circuit temperature is too high or the voltage is too high. The dual protection circuit is connected to the MCU main control.

[0049] The dual protection circuit includes thermistors NTC1, NTC2, operational amplifiers U1, U2,

[0050] One end of the thermistor NTC1 is connected to the positive terminal of the operational amplifier U1 and then to the 3V3 terminal through a 1k ohm resistor. The other end of the thermistor NTC1 is grounded.

[0051] One end of the thermistor NTC2 is connected to the positive terminal of the operational amplifier U2 and then to the 3V3 terminal through a 1k ohm resistor. The other end of the thermistor NTC1 is grounded.

[0052] Operational amplifier U1 is connected to the ADC1 pin of the MCU main controller, and operational amplifier U2 is connected to the ADC3 pin of the MCU main controller.

[0053] The thermistor NTC1 is close to the MOS tube Q1 and divides the voltage with the resistor. The ADC1 pin of the MCU main controller collects its voltage. If the temperature is too high, the DAC1 pin can be controlled to turn off the MOS tube Q1 and stop the current output.

[0054] The thermistor NTC2 is close to the MOS tube Q2 and divides the voltage with the resistor. The ADC3 pin of the MCU main controller collects its voltage. If the temperature is too high, the DAC1 pin can be controlled to turn off the MOS tube Q1, which will stop the current output and pass the temperature protection circuit.

[0055] ADC2 collects the voltage of the positive power supply. If the voltage is too high, the DAC1 pin will be set to shut down the MOS tube Q1.

[0056] ADC3 collects the converted voltage of the negative power supply. If the voltage collected by ADC3 is too high, the DAC2 pin will be set to shut down the MOS tube Q2.

[0057] The technical solution of the present invention overcomes the shortcomings of the background technology. The board-level resistive load solution of the present invention can automatically check the positive and negative poles of the power supply, and perform a current source test on the positive power supply and a current sink test on the negative power supply. The system adopts an automatic shifting function to set different current ranges, and places power devices on a board outside the electronic load board, reducing its size and increasing its integration.

[0058] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A small-volume, wide-range electronic load circuit, characterized by: It includes an electronic load board and an adapter board. The electronic load board is provided with a sampling module and an operational amplifier module connected to the sampling module. The adapter board is provided with an MCU main control, a power module, and a protection module. The MCU main control is connected to the operational amplifier module, the power module, and the protection module. The MCU main control controls the power module to source current or sink current according to the positive and negative values of the collected voltage, and controls the gear of the source current or sink current through the sampling module and the operational amplifier module.

2. The small-volume, wide-range electronic load circuit according to claim 1, characterized in that: The sampling module includes a first sampling group and a second sampling group, the operational amplifier module includes operational amplifiers U3, U4, U5, and U6, and the power module includes MOS tubes Q1 and Q2, wherein: The drain of the MOS tube Q1 is connected to the positive power supply terminal and to the ADC2 pin of the MCU main control, the source of the MOS tube Q1 is connected to the first sampling group and to the positive terminal of the operational amplifier U3, the first sampling group is connected to the negative terminal of the operational amplifier U3 and to ground, the operational amplifier U3 is connected to the negative terminal of the operational amplifier U4 and to the ADC5 pin of the MCU main control, the positive terminal of the operational amplifier U4 is connected to the DAC1 pin of the MCU main control, and the operational amplifier U4 is connected to the gate of the MOS tube Q1; The drain of the MOS tube Q2 is connected to the negative power supply terminal and to the ADC4 pin of the MCU main control, the source of the MOS tube Q2 is connected to the second sampling group and to the positive terminal of the operational amplifier U5, the second sampling group is connected to the negative terminal of the operational amplifier U5 and to ground, the operational amplifier U5 is connected to the negative terminal of the operational amplifier U6 and to the ADC6 pin of the MCU main control, the positive terminal of the operational amplifier U6 is connected to the DAC2 pin of the MCU main control, and the operational amplifier U6 is connected to the gate of the MOS tube Q2.

3. The small-volume, wide-range electronic load circuit according to claim 2, characterized in that: The first sampling group and the second sampling group each include a plurality of sampling resistors with different resistance values. The source of the MOS transistor Q1 is connected to the multiple sampling resistors of the first sampling group, and the source of the MOS transistor Q2 is connected to the multiple sampling resistors of the second sampling group; Each sampling resistor in the first sampling group is connected to the negative terminal of the operational amplifier U3 through a single connected switch element, and each sampling resistor in the second sampling group is connected to the negative terminal of the operational amplifier U5 through a single connected switch element.

4. The small-volume, wide-range electronic load circuit according to claim 1, characterized in that: The protection module includes a dual protection circuit that cuts off current output when the circuit temperature is too high or the voltage is too high, and the dual protection circuit is connected to the MCU main control.

5. The small-volume, wide-range electronic load circuit according to claim 4, characterized in that: The dual protection circuit includes thermistors NTC1, NTC2, operational amplifiers U1, U2, One end of the thermistor NTC1 is connected to the positive terminal of the operational amplifier U1 and connected to the 3V3 terminal through a 1k ohm resistor, and the other end of the thermistor NTC1 is grounded; One end of the thermistor NTC2 is connected to the positive terminal of the operational amplifier U2 and connected to the 3V3 terminal through a 1k ohm resistor, and the other end of the thermistor NTC1 is grounded; The operational amplifier U1 is connected to the ADC1 pin of the MCU main controller, and the operational amplifier U2 is connected to the ADC3 pin of the MCU main controller.