Digital amplifier of 96 kHz PWM frequency with 91dB dynamic range and 0.13% THD+N at full modulation

Author

Park Kyoungsoo ; Zaegyoo Hah ; Koeng-Mo Sung

Author_Institution

Sch. of Electr. Eng. & Comput. Sci. & Inst. of New Media & Commun., Seoul Nat. Univ., Seoul, South Korea

Volume

58

Issue

4

fYear

2012

fDate

11/1/2012 12:00:00 AM

Firstpage

1307

Lastpage

1313

Abstract

A Pulse Width Modulation digital amplifier is implemented at 96 kHz of switching frequency, significantly lower than the conventional 384 kHz. This provides numerous advantages: less computational time; lower thermal burden on the output stage power MOSFETs; higher Modulation Index; and lower production cost. The implemented system provides 91dB of Dynamic Range with optimized Noise-Shaper coefficients and satisfies the need of most consumer audio products. The Total Harmonic Distortion + Noise ratio, with the optimized clipping compensation of the NS overflow, is 0.13% at full modulation. The reduced THD+N and switching loss increase the maximum output power at fixed levels of power supply voltage and speaker impedance.

Keywords

amplifiers; noise; power MOSFET; pulse width modulation; switching; PWM frequency; clipping compensation; frequency 384 kHz; frequency 96 kHz; full modulation; modulation index; optimized noise-shaper coefficients; output stage power MOSFET; power supply voltage; pulse width modulation digital amplifier; speaker impedance; switching frequency; total harmonic distortion-noise ratio; Dynamic range; Microwave integrated circuits; Noise; Power amplifiers; Power generation; Pulse width modulation; Modulation Index; Noise-Shaper; PWM frequency; digital amplifier;

fLanguage

English

Journal_Title

Consumer Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0098-3063

Type

jour

DOI

10.1109/TCE.2012.6415000

Filename

6415000