A per-channel LSI codec for PCM communications
- 1 February 1979
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Journal of Solid-State Circuits
- Vol. 14 (1) , 7-13
- https://doi.org/10.1109/JSSC.1979.1051135
Abstract
An LSI codec for voiceband signals is presented. A modified counting type encoding technique is employed to realize the codec, which uses coarse and fine reference current to discharge the integrating capacitor. The technique makes possible the realization of a high-speed counting-type codec for voice signals without imposing severe requirements on device parameters. This codec is composed of two LSI chips, i.e., a bipolar chip and an NMOS chip. An estimation sample of the LSI codec is fabricated and evaluated. Measured data of the codec performance are very close to the theoretically expected value. The performance assures that the device can be applied to channel banks, local switches, toll switches, and EPBXs.Keywords
This publication has 2 references indexed in Scilit:
- A segmented μ-255 law PCM voice encoder utilizing NMOS technologyIEEE Journal of Solid-State Circuits, 1976
- A Unified Formulation of Segment Companding Laws and Synthesis of Codecs and Digital CompandorsBell System Technical Journal, 1970