Constant voltage and constant current control circuit and constant voltage and constant current switching compensation method

Abstract

The invention discloses a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method. The method includes utilizing a constant current error amplifier (CCEA) to generate a constant current signal, utilizing a constant voltage error amplifier (CVEA) to generate a constant voltage signal, receiving the constant current signal and the constant voltage signal to control a controlled system, compensating current extracted by the CCEA from the CVEA in a period that the controlled system works in a constant voltage status and output current is approximate to a constant current value, and compensating current provided by the CVEA to the CCEA in a period that the controlled system works in a constant current status and output voltage is approximate to a constant voltage value. The constant voltage and constant current control circuit has the advantages that starting from basic reasons for interference in a switching period from the CCEA to the CVEA, output of the CCEA and the CVEA in a constant voltage and constant current switching period is compensated, so that a current range of non-constant voltage and non-constant current in the constant voltage and constant current switching period is eliminated, and the circuit can realize lossless switching between constant voltage and constant current.

Description

technical field [0001] The invention relates to a constant voltage and constant current circuit, in particular to a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method. Background technique [0002] In the control system, constant voltage and constant current control is realized by controlling the duty cycle. figure 1 Shown is an existing specific structure, and this specific method is only used as an example for illustration, such as figure 1 As shown, the main modules of the circuit include: a constant current error amplifier 101 (constant current error amplifier, CCEA for short), a constant voltage amplifier 102 (constant voltage error amplifier, CVEA for short), and a state controller 103 . Among them, CVEA102 works when the controlled system works in a constant voltage state, and is used to control the constant output voltage. CCEA101 works when the controlled system works in a constant current...

AI Technical Summary

Problems solved by technology

[0018] The object of the present invention is to provide a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method to solve the problem of the c

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