A per-channel LSI codec for PCM communications

Author

Yano, Kaoru ; Amano, Haruo ; Nakajima, Masahiko ; Shimizu, Hiroaki

Volume

14

Issue

1

fYear

1979

Firstpage

7

Lastpage

13

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

Code convertors; Digital integrated circuits; Encoding; Large scale integration; Pulse-code modulation; Telephone networks; code convertors; digital integrated circuits; encoding; large scale integration; pulse-code modulation; telephone networks; Capacitors; Codecs; Crosstalk; Large scale integration; Noise generators; Phase change materials; Semiconductor device noise; Switches; Telephony; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.1979.1051135

Filename

1051135