Regulation circuit for output amplitude of switch power supply

Abstract

The invention discloses a regulation circuit for output amplitude of a switch power supply. The regulation circuit comprises a detection module, a delay module, a latch module and a regulation module; the detection module is used for outputting conversion indication signals with different electric levels when the positive pulse of a zero-cross detection signal occurs within or after a time period after the appearance of a falling edge of a drive signal; the delay module is used for outputting a delay signal after the drive signal is delayed; the latch module is used for outputting a regulation signal with a low electric level when a positive pulse of the delay signal appears, and outputting a regulation signal with a high electric level when the positive pulse of the conversion indication signal appears; and the regulation module is used for outputting different compensation voltages when the regulation signal is at the low electric level and the high electric level. In comparison with the prior art, change of an input power supply can be detected without an extra hardware resource, the output amplitude is regulated correspondingly, not only the cost is reduced, but also the system reliability design becomes simpler, and the regulation circuit for the output amplitude of the switch power supply can be widely applied.

Description

technical field [0001] The invention relates to the field of switching power supplies, in particular to a circuit for adjusting the output range of a switching power supply. Background technique [0002] As we all know, specific applications require AC power to be input to the switching power supply only within a specific phase interval, and the phase of the AC power input is adjusted through a regulator. The switching power supply circuit needs to detect changes in the input power and adjust the output amplitude accordingly, and finally realize The purpose of adjusting the output of the switching power supply through a regulator. [0003] For the traditional switching power supply output amplitude adjustment circuit, additional chip pins and external high-voltage detection circuits are required to detect changes in the input power supply, and low-frequency filter circuits are required to further process the detection results, which not only consumes more hardware resources,...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the need for additional chip pins and external high-voltage detection circuits to detect changes in input power in the prior art, and the need for additional low-frequency filter circuits to process the detection results, resulting in hardware resource consumption Too many defects, complicated reliability design, etc., provide an adjustment circuit that can detect the change of the input power supply without additional chip pins, and can also adjust the output amplitude of the switching power supply according to the change of the input power supply

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