Title :
An integrated electronic telephone circuit
Author :
Akram, M. Faheem ; Pace, W. David
Abstract :
An integrated electronic telephone circuit (ETC) providing all the necessary elements of a telephone station apparatus is described. The ETC includes a speech network, tone ringer, dual-tone multifrequency (DTMF) dialer and DC line interface circuit. A microprocessor port facilitates automatic dialing features under control of a separate microprocessor. The speech network and dialer circuits operate with instantaneous input voltage as low as 1.4 V. The DTMF generator incorporates a high-precision frequency synthesis technique. Because of the reduction of frequency errors, an inexpensive ceramic resonator can be used as the frequency reference for the dialer. A linear/I/SUP 2/L process with two-layer metal interconnects is used to fabricate the 125/spl times/146 mil ETC die.
Keywords :
Bipolar integrated circuits; Communications computer control; Integrated injection logic; Linear integrated circuits; Telephone lines; Telephone sets; bipolar integrated circuits; communications computer control; integrated injection logic; linear integrated circuits; telephone lines; telephone sets; Automatic control; Ceramics; Circuit synthesis; Frequency synthesizers; Integrated circuit interconnections; Low voltage; Microprocessors; Network synthesis; Speech synthesis; Telephony;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.1983.1052018
