Digital pulse-width modulator with spread-spectrum emission reduction

Abstract

Pulse-width modulated power-stages are used in many power-electronic applications because of their high efficiency. They are known to be a root cause for electromagnetic emission problems if no countermeasures are taken. This work presents a digital pulse-width modulator with an emission reduction method based on spread-spectrum modulation techniques. The proposed method is analyzed in detail, and two possible digital implementations are discussed. The implementations are compared in terms of chip-area and power consumption. Finally, an application of the proposed digital pulse-width modulator in a digitally-controlled Class-D audio amplifier is presented to show the feasibility of the concept. Using an FPGA prototype, a measured emission reduction of up to 9.5 dB is achieved.Keywords: pulse-width modulator; spread-spectrum modulation; electromagnetic emission; Class-D amplifier Digitaler Pulsweitenmodulator mit Spread-Spectrum-Emissionsreduktion. Pulsweitenmodulierte Leistungsstufen werden aufgrund ihres hohen Wirkungsgrades in vielen leistungselektronischen

A Comprehensive Review on FPGA based PWM techniques for DC-DC converters

“…Primarily, there is a need of PWM wave in switched-mode power supplies (SMPS) such as servo-motor drivers, DC-DC converters, and power amplifiers. PWM methods would enhance the power efficiency results in more than 95% in some of the recent power-electronic circuits (Karaca et al 2018).…”