Title :
An adaptive analog continuous-time CMOS biquadratic filter
Author :
Kwan, Tom ; Martin, Ken
Author_Institution :
Analog Devices, Norwood, MA, USA
Abstract :
An adaptive analog continuous-time biquadratic filter is realized in a 2-μm digital CMOS process for operation at 300 kHz. The biquad implements the notch, bandpass, and lowpass transfer functions. The update method is based on a LMS algorithm which adapts the notch frequency to minimize the power at the notch filter output. Applications include FM demodulators (linear and frequency shift keying), clock extractors, and frequency acquisition aids for phase-locked loops and Costas loops. Measured results from experimental prototypes are presented
Keywords :
CMOS integrated circuits; active filters; adaptive filters; band-pass filters; linear integrated circuits; low-pass filters; notch filters; 2 micron; 300 kHz; CMOS; Costas loops; FM demodulators; LMS algorithm; adaptive analogue filter; biquadratic filter; clock extractors; continuous-time; frequency acquisition aids; lowpass transfer functions; notch filter output; notch frequency; phase-locked loops; update method; Adaptive filters; Band pass filters; CMOS process; Clocks; Demodulation; Digital filters; Frequency shift keying; Least squares approximation; Phase locked loops; Transfer functions;
Conference_Titel :
Custom Integrated Circuits Conference, 1991., Proceedings of the IEEE 1991
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0015-7
DOI :
10.1109/CICC.1991.164118
