Multimode frequency controller and switch power supply frequency control method

Abstract

The invention provides a multimode frequency controller and a switch power supply frequency control method in order to simplify the structure, lower the design difficulty and the manufacture difficulty, reduce the area, lower the power consumption and the like. The multimode frequency controller comprises a capacity, a voltage and current conversion module, a frequency control module and a frequency generating module, wherein the voltage and current conversion module is used for converting a load feedback voltage into a feedback current, the feedback voltage is in positive correlation with a load value, the feedback current values correspond to the feedback voltage values one by one; the frequency control module is used for charging the capacitor according to the feedback current obtained by the conversion of the voltage and current conversion module and jumping the state of an output module when the capacitor is charged to the preset voltage or the voltage of the capacitor is higher than the preset voltage and an edge detection signal of a power pipe control signal arrives; and the frequency generating module is used for generating a power pipe control signal of a new working frequency according to the output signal of the frequency control module.

Description

technical field [0001] The invention relates to the field of switching power supplies, in particular to a multi-mode frequency controller and a switching power supply frequency control method. Background technique [0002] In recent years, by increasing the operating frequency of the switching power supply, the efficiency of the switching power supply has been improved and the size of the switching power supply has been reduced. However, the increased operating frequency has also brought greater switching losses. At present, it is mainly through high-frequency soft switching technology to resolve this contradiction. [0003] Quasi-resonant technology is a kind of high-frequency soft switching technology. Based on quasi-resonant technology, the industry has developed a multi-mode quasi-resonant frequency controller. Common multi-mode quasi-resonant frequency controllers work as follows: [0004] The power tube current or voltage is controlled by parasitic devices to change ...

AI Technical Summary

Problems solved by technology

[0012] Through the above principles, the existing quasi-resonant frequency controller realizes the adjustment of the operating frequency of the switching power supply according to different loads. However, it can be seen from the circuit structure that the existing quasi-resonant frequency controller uses multiple comparators. When the circuit is implemented, It is necessary to consider the design requirements of the internal comparator, which will increase the difficulty of design and manufacture. In addition, too many comparators will cause a series of problems such as large area of ​​the controller and increased power consumption.

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