A cross-regulation rate control circuit and method for a multi-channel output power supply

Abstract

The invention relates to a cross-regulation rate control circuit and method of a multi-channel output power supply, which belongs to the technical field of cross-regulation rate control and solves the problems of low efficiency and low precision of main output voltage in the prior art. The circuit includes multiple output power supply, coupling inductor L1 and feedback control circuit; multiple output power supply includes input power supply Uin, main output Vo1 and auxiliary output Vo2; coupling inductor L1 is connected between main output Vo1 and auxiliary output Vo2 for The output voltage of the main output Vo1 is regulated according to the output voltage of the auxiliary output Vo2; the feedback control circuit includes a PI controller and a PWM generator, the PI controller is used to receive the output voltage of the main output Vo1 as a feedback signal, and regulates the PWM generator output with a corresponding The PWM signal of the empty ratio, and then controls the power supply of the input power supply Uin to the multi-channel output power supply. The circuit realizes the indirect closed-loop control of the auxiliary output Vo2, and improves the output voltage control effect of the auxiliary output.

Description

technical field [0001] The invention relates to the technical field of cross regulation rate control, in particular to a cross regulation rate control circuit and method of a multi-channel output power supply. Background technique [0002] For a multi-output flyback switching power supply using a multi-winding transformer, one of the outputs is usually selected as the main output for output voltage feedback adjustment, and the other outputs are used as auxiliary outputs. Ideally, the main output voltage and auxiliary output voltage meet the turn ratio relationship of the corresponding windings of the transformer. As long as the main output voltage is kept stable, the auxiliary output voltage can also be kept stable according to a certain ratio. However, due to the leakage inductance between transformer windings and other reasons in actual situations, the voltage of the auxiliary output will not only change with the change of its own load, but also change with the load of oth...

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Problems solved by technology

[0006] In view of the above analysis, the present invention aims to provide a multi-channel output power supply cross-regulation rate control circuit and method to solve the problems of high power consumption, low efficiency and low output voltage accuracy of the existing multi-channel output power supply cross-regulation rate method. question

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