Conversion of a single-bit signal into a PWM signal

Author

Li, Weibo ; Orino, Yuichiro ; Kurosawa, Minoru Kuribayashi ; Katagiri, Takashi

Author_Institution

Dept. of Adv. Appl. Electron., Tokyo Inst. of Technol., Kanagawa, Japan

Volume

A

fYear

2004

fDate

21-24 Nov. 2004

Firstpage

519

Abstract

A novel pulse width modulation (PWM) signal generation technique is proposed. The generator converts a single-bit digital signal into a PWM signal without a ramping waveform generator. The proposed PWM signal generators are based on the concept of Delta-Sigma (ΔΣ) modulation. A comparator with hysteresis is used instead of a quantizer in the ΔΣ modulator. The switching frequency of the PWM signal decreased with increase of the hysteresis width. The noise-shaped output is obtained and a high signal to noise ratio (SNR) is achieved. In this paper, a 1st-order PWM signal generator is presented. In order to obtain a much higher precision PWM signal a 2nd-order PWM signal generator is discussed. But the 2nd-order PWM is unstable. Hence, PI compensation is applied to stabilize the modulator. A better PWM signal generator with PI compensation is presented. From the improved generator, a low distortion PWM signal was generated, and the SNR of output signal is increased about 20 dB compared to the 1st-order PWM signal generator.

Keywords

delta-sigma modulation; pulse width modulation; signal processing; waveform generators; Delta-Sigma modulation; PI compensation; PWM signal generator; pulse width modulation signal generation; signal to noise ratio; single-bit signal; switching frequency; waveform generator; Pulse width modulation;

fLanguage

English

Publisher

ieee

Conference_Titel

TENCON 2004. 2004 IEEE Region 10 Conference

Print_ISBN

0-7803-8560-8

Type

conf

DOI

10.1109/TENCON.2004.1414471

Filename

1414471