Frequency modulation device, switching power supply and frequency modulation method thereof

Abstract

The invention discloses a frequency modulation device, a switching power supply and a frequency modulation method thereof. The device comprises a waveform generation unit (10) for generating a periodic signal required for frequency modulation of a clock signal of a switching power supply to be controlled; a frequency modulation unit (20) configured to perform voltage-current conversion and operation processing based on the periodic signal to obtain a frequency modulation current required for frequency modulation of a clock signal of the switching power supply to be controlled; an RC oscillation unit (30) for performing an RC oscillation process based on the frequency modulation current to obtain a frequency vibration signal as a clock signal of the switching power supply to be controlled.The scheme of the invention can solve the problem that the EMC performance of the switching power supply using the fixed frequency oscillator in the prior art is poor, and achieves the effect of improving the EMC performance.

Description

technical field [0001] The invention belongs to the technical field of switching power supplies, and in particular relates to a frequency modulation device, a switching power supply and a frequency modulation method thereof, in particular to a device for implementing a brand-new frequency modulation technology, a switching power supply with the device and a frequency modulation method thereof. Background technique [0002] In the development of the integrated circuit industry, switching power supply systems are more and more widely used. At the same time, the interference performance (ie, EMC) of the switching power supply system itself to the outside world will be subject to increasingly stringent requirements and restrictions. In the principle of switching power supply, an oscillator module is needed. However, the output frequency of the traditional oscillator is a fixed frequency, and the EMC performance of the switching power supply using the fixed frequency oscillator ...

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Problems solved by technology

[0003] The object of the present invention is to, in view of the above defects, provide a frequency modulation device, a switching power supply and a frequency modulation method thereof, to solve the problem of poor EMC performance of switching power supplies using fixed frequency oscillators in the prior art, to achieve improved EMC performance Effect

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