Title :
SIGFRED: a low-power DTMF and signaling frequency detector
Author :
Becker, Rolf ; Mulder, Jaap
Author_Institution :
Faselec AG, Zurich, Switzerland
fDate :
7/1/1991 12:00:00 AM
Abstract :
A CMOS circuit is presented containing an analog switched-capacitor processor for detection of dual-tone multifrequency, (DTMF) and signaling tones on a telephone subscriber line and a digital detection algorithm for postprocessing. The major issues for the design were that it should be compatible with a CMOS fabrication process for microcontrollers to be included as an on-chip component and that its power consumption should be as low as possible. It has been designed to work with a current of less than 0.5 mA at low supply voltages (2.5-3 V). The maximum supply voltage is limited to 6 V by the process
Keywords :
CMOS integrated circuits; detector circuits; switched capacitor networks; telephone receivers; 0.5 mA; 2.5 to 6 V; CMOS circuit; DTMF; SIGFRED; analog switched-capacitor processor; digital detection algorithm; dual-tone multifrequency; low-power; monolithic IC; postprocessing; signaling frequency detector; telephone subscriber line; CMOS analog integrated circuits; CMOS digital integrated circuits; CMOS process; Detection algorithms; Detectors; Frequency; Signal detection; Signal processing; Switching circuits; Telephony;
Journal_Title :
Solid-State Circuits, IEEE Journal of
