Title :
A 3rd order 1.5-bit continuous-time (CT) Sigma-Delta (ΣΔ) modulator optimized for Class D audio power amplifier
Author :
De Melo, João ; Paulino, Nuno
Author_Institution :
Dept. de Eng. Electrotec., Univ. Nova de Lisboa, Caparica, Portugal
Abstract :
This paper presents a 3rd order 1.5-bit ΣΔ modulator with distributed feedback and local resonator feedback for a Class D audio amplifier. In order to improve the signal-to-noise-and-distortion ratio (SNDR), without increasing the oversampling ratio (OSR) or the order of the modulator, the modulator uses transmission zeros and 1.5-bit quantization. High level simulations of the modulator show that it has a maximum SNDR value of 82.4 dB and a dynamic range (DR) of 76 dB, for a signal bandwidth of 18 kHz and a sampling frequency of 1.2 MHz. The use of a full-bridge output stage allows 1.5-bit quantization.
Keywords :
audio-frequency amplifiers; optimisation; power amplifiers; sigma-delta modulation; ΣΔ modulator optimisation; 3rd order 1.5-bit continuous-time sigma-delta modulator; OSR; SNDR; bandwidth 18 kHz; class D audio power amplifier; distributed feedback; frequency 1.2 MHz; full-bridge output stage; local resonator feedback; oversampling ratio; signal-to-noise-and-distortion ratio; Bandwidth; Distributed feedback devices; Electromagnetic interference; Frequency modulation; Power supplies; Switches; Audio; Class D amplifier; Continuous-Time (CT) Sigma-Delta (ΣΔ);
Conference_Titel :
Mixed Design of Integrated Circuits and Systems (MIXDES), 2010 Proceedings of the 17th International Conference
Conference_Location :
Warsaw
Print_ISBN :
978-1-4244-7011-2
Electronic_ISBN :
978-83-928756-4-2
