Title :
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
fDate :
11/1/2012 12:00:00 AM
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;
Journal_Title :
Consumer Electronics, IEEE Transactions on
DOI :
10.1109/TCE.2012.6415000
