A High Precision Adjustable Current Source Circuit

Abstract

The invention relates to a high-precision adjustable current source circuit. The circuit comprises a programmable voltage source unit, a first operational amplifier, a second operational amplifier andan MCU; The same-phase input end of the first operational amplifier and the same-phase input end of the second operational amplifier are connected through a buffer resistor, one end of the programmable voltage source unit is connected with the MCU, the other end of the programmable voltage source unit is connected with the same-phase input ends of the first operational amplifier and the second operational amplifier through buffer resistors respectively, the reverse input end of the first operational amplifier is connected with the reverse input end of the second operational amplifier after being connected with the output end, and the output end of the second operational amplifier is connected with the MCU. The voltage of the two ends of a fifth resistor Rs is detected through the MCU andserves as feedback to regulate the output of a voltage source, and thus constant-current-source, high-stability and high-precision output is achieved. The MCU detects and controls the voltage source so that regulation of a current source can be achieved, and such a circuit design greatly reduces the complexity of a source meter.

Description

technical field [0001] The invention relates to the fields of instrumentation and electronic measurement, in particular to a high-precision adjustable current source circuit applicable to high-precision source meters. Background technique [0002] High-precision adjustable current source is one of the most commonly used equipment in the electronic measurement industry, and is widely used in industry and laboratories. [0003] In the traditional source meter design, the voltage source and the current source are usually two independent modules, the circuit structure is complex, and the cost of making the PCB is relatively high. However, in many current source designs today, Zener diodes and triodes are mainly used as implementation methods. Voltage fluctuations easily affect the reference output of diodes, and a small current flows into the base of the triode. These factors will affect the stability of the constant current source. and precision. Contents of the invention ...

AI Technical Summary

Problems solved by technology

[0003] In the traditional source meter design, the voltage source and current source are usually two independent modules, the circuit structure is complex, and the cost of making PCB is high

However, in many current source designs today, Zener diodes and triodes are mainly used as implementation methods. Voltage fluctuations easily affect the reference output of diodes, and a small current flows into the base of the triode. These factors will affect the stability of the constant current source. and precision

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