Fourier series analysis of the nonlinearities in analog closed-loop PWM class D amplifiers

Author

Shu, Wei ; Chang, Joseph S. ; Ge, Tong ; Tan, Meng Tong

Author_Institution

Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ.,, Singapore

fYear

2006

fDate

21-24 May 2006

Lastpage

1385

Abstract

We derive Fourier series expressions for modeling analog closed-loop PWM class D amplifiers. Based on our derived expressions, we are able to analyze the mechanisms of several nonlinearities, specifically the power supply noise and fold-back distortions. We investigate the influence of the finite loop gain on these nonlinearities, and we show that those nonlinearities can be effectively suppressed by the higher loop gain. We verify our analysis by computer simulations and also on the basis of experimental measurements. The derived expressions are practically useful as they provide insights to a designer for PWM class D amplifier designs

Keywords

Fourier series; analogue circuits; power amplifiers; power supply circuits; pulse width modulation; Fourier series analysis; PWM amplifiers; analog closed-loop amplifier; class D amplifiers; finite loop gain; fold-back distortions; nonlinearities; power supply noise; pulse width modulation; Computer simulation; Filters; Fourier series; Frequency; Heat sinks; MATLAB; Mathematical model; Power amplifiers; Power supplies; Pulse width modulation;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2006. ISCAS 2006. Proceedings. 2006 IEEE International Symposium on

Conference_Location

Island of Kos

Print_ISBN

0-7803-9389-9

Type

conf

DOI

10.1109/ISCAS.2006.1692852

Filename

1692852