A monolithic Sigma-Delta A/D and D/A converter with filter for broadband speech coding

This 5V 14b 16ksample/s CODEC meets the analog requirements for CCITT broadband speech coding with 0.3.dB passband ripple and 80dB dynamic range. A continuous-tim3 sigma-delta coder with specialized DSP for FIR filtering are integrated on a 31mmü3fm CMOS chip dissipating 125 mW.