Title :
A Programmable Impedance Matching Circuit for Voiceband Modems
Author :
Hershbarger, Russell A. ; Jia, Wenyan ; Tey, Kiam M. ; Fukahori, Kiyoshi ; Hurst, Paul J. ; Kapoor, Manprit
Author_Institution :
Teridian Semicond., Mountain View
Abstract :
A line impedance-matching circuit for a voiceband modem is described. The circuit can be programmed to realize four different impedances. A switched-capacitor filter is used to generate the required transfer functions. The impedance-matching concept and circuits are described. Measured results are presented that show that the four impedances are realized with sufficient accuracy for voiceband modems. The circuit was fabricated in a standard 0.35-mum mixed-signal CMOS process.
Keywords :
CMOS integrated circuits; impedance matching; mixed analogue-digital integrated circuits; modems; programmable circuits; switched capacitor filters; line impedance-matching circuit; mixed-signal CMOS process; programmable impedance matching circuit; size 0.35 mum; switched-capacitor filter; transfer function; voiceband modem; Analog-digital conversion; CMOS integrated circuits; CMOS process; Capacitors; Digital filters; Digital signal processing; Feeds; Impedance matching; Interpolation; Modems; Impedance matching; modem; switched-capacitor circuit;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2007.914298
