Multi-period random digit pulse-width modulation circuit and method

Abstract

The invention relates to a multicycle random digital impulse width modulation circuit and a method thereof. The multicycle random digital impulse width modulation circuit comprises a multicycle random digital impulse width modulation module, a linear feedback shift register module and a multiplexer module; wherein, the multicycle random digital impulse width modulation module is connected with the linear feedback shift register module which is connected with the multiplexer module. The multicycle random digital impulse width modulation method is split jointed a forward-directional toothed wave and back-directional toothed wave. The technical scheme of the invention can choose one among toothed wave, pyramidal wave and random impulse width modulation according to the requirements, thereby having great flexibility. The realization of the random impulse width modulation can realize frequency spectrum spreading, thereby effectively reducing the EMI conduction and radiation level of DPWM.

Description

technical field [0001] The invention belongs to the technical field of power electronics and relates to pulse width modulation technology, in particular to a multi-period random digital pulse width modulation circuit and method. Background technique [0002] Fixed-period PWM (Pulse Width Modulation) pulse width modulation technology is widely used in power electronics technology, but the working waveform of the fixed-period PWM modulation signal is a periodic square wave, which contains rich high frequency near the switching frequency and the integer multiple of the switching frequency. Sub-harmonics, these undesired harmonics will reduce the electromagnetic compatibility quality of the whole system, produce a strong broadband electromagnetic emission source, generate large noise in other circuits, and even make other circuits unable to work normally. For the motor, it is easy to generate large audio noise and vibration in the motor. Determined by the characteristics of the...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the existing technology in the vicinity of the switching frequency or the integer multiple of the switching frequency, there is a strong narrow-band audio noise, the strength and spectral characteristics of the noise will make the system and the surrounding circuits prone to noise in the audio range Interference, so that the motor produces audio noise and vibration and other technical problems, the invention provides a multi-cycle random digital pulse width modulation circuit

[0004] In order to solve the existing technology in the vicinity of the switching frequency or the integer multiple of the switching frequency, there is a strong narrow-band audio noise, the strength and spectral characteristics of the noise will make the system and the surrounding circuits prone to noise in the audio range Interference, so that the motor produces audio noise and vibration and other technical problems, the invention provides a multi-period random digital pulse width modulation method

Images