Title :
Automatic tuning of RC filters and fast automatic gain control for CMOS low-IF transceiver
Author :
Oshima, Takashi ; Maio, Kenji ; Hioe, Willy ; Shibahara, Yoshiyuki ; Doi, Takeshi
Author_Institution :
Central Res. Lab., Hitachi Ltd., Tokyo, Japan
Abstract :
Automatic tuning of RC filters and fast automatic gain control (AGC) of cascaded programmable amplifiers were proposed and verified by a 0.18 μm CMOS prototype IC. The tuning circuit includes a dummy 1st-order filter, a comparator and a simple digital circuit and tunes ±28 % time-constant variation of filters within ±4.4 % accuracy. The AGC circuit adopts a novel feedforward technique with a digital timing control, which enables one-shot gain control and thus a fast settling.
Keywords :
CMOS integrated circuits; RC circuits; active filters; automatic gain control; circuit tuning; comparators (circuits); feedforward; integrated circuit design; radiofrequency amplifiers; transceivers; 0.18 micron; AGC; CMOS low-IF transceiver; RC filter automatic tuning; cascaded programmable amplifiers; comparator; digital timing control; digital tuning circuit; dummy first-order filter; fast automatic gain control; fast settling time; feedforward; filter time-constant variation; one-shot gain control; CMOS digital integrated circuits; CMOS integrated circuits; Circuit optimization; Digital circuits; Digital filters; Gain control; Prototypes; Timing; Transceivers; Tuned circuits;
Conference_Titel :
Custom Integrated Circuits Conference, 2003. Proceedings of the IEEE 2003
Print_ISBN :
0-7803-7842-3
DOI :
10.1109/CICC.2003.1249348
