Title :
A VHF OTA-C Topology Having Low Phase Error With Gm Tuning
Author :
Yadav, Kshitij ; Mandal, Pradip
Author_Institution :
Electron. & Electr. Commun. Eng. Dept., Indian Inst. of Technol., Kharagpur
Abstract :
In sub-micron process, while speed of device is suitable for VHF applications, phase variation at unity gain frequency of OTA-C cell with frequency tuning is high. This is mainly because of high value of channel length modulation parameter of the devices. A technique which makes the phase response robust to frequency tuning is proposed here. Based on this technique a VHF CMOS OTA-C cell is designed in a 0.18 mum CMOS process. The phase error of the cell is within 0.3deg, over a range of unity-gain frequency from 300 MHz to 1.2 GHz. The small phase error over a wide range of frequency implies the use of just one Q-tuning loop for all the integrators having unity-gain frequency within this range. Also this makes this circuit suitable for application in programmable transfer function filters
Keywords :
CMOS integrated circuits; Q-factor; VHF filters; circuit tuning; operational amplifiers; programmable filters; transfer functions; 0.18 micron; 0.18 mum CMOS process; 300 MHz to 1.2 GHz; Gm tuning; OTA-C cell; Q-tuning loop; VHF application; channel length modulation parameter; frequency tuning; integrators; operational transconductance amplifier; phase error; phase response; programmable transfer function filters; submicron process; CMOS process; CMOS technology; Circuit topology; Filters; Frequency; Q factor; Robustness; Tail; Transconductance; Tuning;
Conference_Titel :
Communications, Circuits and Systems Proceedings, 2006 International Conference on
Conference_Location :
Guilin
Print_ISBN :
0-7803-9584-0
Electronic_ISBN :
0-7803-9585-9
DOI :
10.1109/ICCCAS.2006.285143
