A micropower low-distortion digital pulsewidth modulator for a digital Class D amplifier

被引：32

作者：

Gwee, BH ^{[1
]}

Chang, JS ^{[1
]}

Li, HY ^{[1
]}

机构：

[1] Nanyang Technol Univ, Sch Elect & Elect Engn, Singapore 639798, Singapore

来源：

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS | 2002年 / 49卷 / 04期

关键词：

Class D amplifiers; delta-compensation (delta C); digital signal processing process; hearing instruments; pulse generator; pulsewidth modulation; sampling process;

D O I：

10.1109/TCSII.2002.801407

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

We describe the design of a micropower digital pulsewidth modulator (PWM) for a hearing instrument Class D amplifier. The PWM embodies a novel delta-compensation (deltaC) sampling process and a novel pulse generator. The deltaC process is sampled at the same low rate as reported algorithmic sampling processes and it features a similar low total harmonic distortion (THD). Its arithmetic computation is however, substantially simplified. We analytically derive the double Fourier series expression for the deltaC process and show that the THD is low. The pulse generator is based on a hybrid 9-b counter 3-b tapped-delay-line. We investigate the compromise between the different design parameters that affect, its power dissipation and THD. The complete proposed PWM features a simple circuit implementation (small IC area), micropower low voltage operation (similar to22.1 muW @ 1.1 V), low sampling rate (48 kHz) and low harmonic distortion (similar to0.2%). thereby rendering it suitable for a practical digital hearing instrument. We verify our design by means of computer simulations and on the basis of experimental measurements.

引用

页码：245 / 256

页数：12

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