An interpolative PCM CODEC with multiplexed digital filters
- 1 December 1980
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Journal of Solid-State Circuits
- Vol. 15 (6) , 1014-1021
- https://doi.org/10.1109/JSSC.1980.1051511
Abstract
An LSI CODEC, an LSI multiplexed digital filter, and an LSI compandor are developed for telephone PCM AD/DA conversion. The total chip count is 1.56 chips per channel. The single-chip interpolative CODEC operates at a 32 kHz sampling rate with a 12-bit linear code input/output, and is implemented in a phosphorus buried emitter IIL process without the need for component value trimming. The digital filter is four-channel multiplexed for both transmitting and receiving directions. It is compactly fabricated with a combinatorial configuration in a 5 /spl mu/m NMOS process. A new word length extension technique was devised to realize an 87 dB dynamic range with the digital filter. The compandor, also fabricated in 5 /spl mu/m NMOS, is 16-channel multiplexed for both directions. All measured characteristics meet CCITT recommendations with sufficient margins. They demonstrate the inherent stability and noise immunity that can be achieved with the interpolation technique of the CODEC and the digital signal processing of the digital filter.Keywords
This publication has 5 references indexed in Scilit:
- Interpolative PCM CODECs with multiplexed digital filtersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1980
- An integrated interpolative PCM decoderIEEE Journal of Solid-State Circuits, 1979
- A Per-Channel A/D Converter Having 15-Segment µ-255 CompandingIEEE Transactions on Communications, 1976
- A new hardware realization of digital filtersIEEE Transactions on Acoustics, Speech, and Signal Processing, 1974
- A Unified Formulation of Segment Companding Laws and Synthesis of Codecs and Digital CompandorsBell System Technical Journal, 1970