A Current Sampling Circuit for Buck Converter Can Eliminate DC Error

Abstract

The invention relates to a current sampling circuit for a BUCK converter and capable of eliminating direct current errors, and belongs to the technical field of current sampling processing. The current sampling circuit comprises a BUCK converter circuit, a current biasing circuit, a current sampling circuit and a direct current error eliminating circuit. The BUCK converter circuit is connected with an externally connected direct current power source and connected with the current sampling circuit synchronously; the current biasing circuit is connected with the current sampling circuit; the current sampling circuit is connected with the direct current error eliminating circuit; and the direct current error eliminating circuit is connected with the current biasing circuit. According to the current sampling circuit for the BUCK converter and capable of eliminating the direct current errors, metal-oxide semiconductor field effect transistors at the high end and the low end in the BUCK converter are subjected to current sampling in real time, the current biasing circuit provides suitable current biasing for the current sampling circuit and the direct current error eliminating circuit, meanwhile, the direct current error eliminating circuit can eliminate the direct current errors existing in the current sampling process, the current sampling precision is improved, and the deficiencythat in a traditional current sampling method, sampling is discontinuous is overcome.

Description

technical field [0001] The invention relates to a current sampling circuit for a BUCK converter capable of eliminating DC errors, and belongs to the technical field of current sampling processing. Background technique [0002] Many electronic products need to know the current of the DC power supply during the working process, especially in circuits that require relatively high current accuracy, not only the real-time current needs to be monitored, but also the real-time sampled current value needs to be fed back to the loop road control. [0003] At present, most of the research focuses on DC transformer sampling and reflecting the current by sampling the voltage across the resistor, but this is not suitable for high-current circuits, nor is it suitable for making the volume small, which will eventually lead to the efficiency of the entire system. Contents of the invention [0004] The technical problem to be solved by the present invention is: the present invention provi...

AI Technical Summary

Problems solved by technology

The whole circuit is small in size and light in weight, which solves the discontinuous sampling characteristics in the traditional current sampling method. The sampling speed is fast, the delay is small, the real-time performance is high, and the accuracy of current sampling is guaranteed.

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