Calibration offset circuit and method for electronic load constant current control loop

Abstract

The present invention provides a calibration offset circuit and method for a constant current control loop of an electronic load, wherein the circuit includes: a calibration DAC unit for outputting voltage; a bias resistor, one end of which is connected to the output end of the calibration DAC unit, and the other end is connected to the output end of the calibration DAC unit. One end is connected with the constant current control loop; the control device is connected with the input end of the calibration DAC unit and the output end of the voltmeter for calibrating the voltage value of the resistance of the external reading circuit, for the input voltage of the constant current control loop is 0 volts , when the voltage value of the voltmeter is not 0 volts, adjust the voltage value output by the calibration DAC unit according to the changing trend of the voltage value of the voltmeter until the measured value of the voltmeter is 0 volts; when the measured value of the voltmeter is 0 volts, calibrate The code value of the DAC in the DAC unit is the offset calibration value of the constant current control loop. The above technical solution realizes the automatic and accurate offset calibration of the constant current control loop of the electronic load, and improves the calibration accuracy and production efficiency.

Description

Technical field [0001] The present invention relates to the field of electronic load technology, and more particularly to a calibration disorder circuit and method for electronic load constant current control loops. Background technique [0002] In an existing electronic load product, the constant current CC (constant current) control loop always has an offset error, that is, when the input control voltage is 0V, the CC control loop does not output 0A, but always outputs a small Current value, this current may be a few milliants, or may be a few tens of milliamps. In order to enable the CC control loop to accurately output the current, the offset current in the loop must be eliminated by calibration, so that when the control voltage is 0V, the CC control loop can output 0A. figure 1 Schematic diagram of CC control loop in existing electronic load products, figure 1 The IOUT is the output current, and the DC represents the DC power supply input from the outside. [0003] At presen...

AI Technical Summary

Problems solved by technology

[0012] To sum up, the disadvantages of the traditional method are: in the process of producing electronic loads, there are possible human errors in the process of calibrating the offset current, which makes it impossible to automate production, and the calibration accuracy and production efficiency are low.

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