A four-channel CMOS codec filter circuit "SICOFI-4"

Cost reduction by integration of complex mixed analog-digital systems on a single chip and an excellent yield to area ratio is a major goal for IC design in the nineties. In this paper, a four-channel codec-filter chip for analog subscriber lines in ISDN-orientated networks is presented, giving an exceptional example for high level system implementation combined with parallel DSP integration and analog circuitry with high performance. The chip combines four analog frontends, digital signal processing realized by different approaches for a sophisticated filter concept in addition with test strategies including digital and analog BIST. The circuit is fabricated in a standard 1-/spl mu/m CMOS technology, needs a single 5-V power supply, and can easily be programmed to world-wide different country specifications and applications.<
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