Title :
A monolithic ΣΔ A/D and D/A converter with filter for broad-band speech coding
Author :
Lerch, Renee G. ; Lamkemeyer, Matthias H. ; Fiedler, Horst L. ; Bradinal, Werner ; Becker, Peter
Author_Institution :
Fraunhofer Inst. of Integrated Circuits & Syst., Duisburg, Germany
fDate :
12/1/1991 12:00:00 AM
Abstract :
The authors present a 5-V-only 14-b, 16 ksamples/s linear codec suitable as the audio part of a CCITT G722 codec. The device uses second-order sigma-delta modulation for both analog/digital (A/D) and digital/analog (D/A) conversion at 2.048 Msamples/s. A time-continuous modulator with integrated antialias filtering is used at the A/D side, obviating the need for an external antialiasing filter. The digital filters for decimation and interpolation are implemented with both a custom digital signal processor (DSP) and specialized hardware. The device was realized with 74000 transistors on a 31-mm2 die in a 3-μm SACMOS technology. A dynamic range of more than 80 dB and a passband ripple of 0.3 dB were attained with A/D and D/A paths in cascade
Keywords :
CMOS integrated circuits; VLSI; analogue-digital conversion; codecs; digital signal processing chips; digital-analogue conversion; speech analysis and processing; 14 bit; 16 kHz; 2.048 MHz; 3 micron; 5 V; CCITT G722 codec; SACMOS technology; audio part; broad-band speech coding; decimation; digital filters; dynamic range; integrated antialias filtering; interpolation; linear codec; passband ripple; second-order sigma-delta modulation; self aligned contact CMOS; sigma delta ADC; sigma delta DAC; time-continuous modulator; Codecs; Delta-sigma modulation; Digital filters; Digital signal processing; Digital signal processors; Dynamic range; Filtering; Hardware; Interpolation; Passband;
Journal_Title :
Solid-State Circuits, IEEE Journal of
