A 2-V CMOS 455-kHz FM/FSK demodulator using feedforward offset cancellation limiting amplifier

• Published in: IEEE journal of solid-state circuits Vol. 36; no. 1; pp. 135 - 138
• Main Authors: Huang, Po-Chiun, Chen, Yi-Huei, Wang, Chorng-Kuang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2001; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Automatic control; CMOS; CMOS technology; Communication system control; Constraining; Demodulation; Demodulators; Detectors; Feedforward; Frequency shift keying; Integrated circuit technology; Intermediate frequency; Limiting; Microprocessors; Offsets; Phase detection; Signal processing
• DOI: 10.1109/4.896238
• ISSN: 0018-9200

This paper presents a low-voltage low-power IF 455-kHz signal processor that contains a three-stage limiting amplifier and an FM/FSK demodulator. The limiting amplifier uses an on-chip feedforward offset cancellation circuit. The FM/FSK demodulator employs a quadrature detector that is composed of an on-chip phase detector and an external tank phase shifter. The demodulation constant is 20 mV/kHz with masimum /spl plusmn/10-kHz frequency deviation. The IF signal processor that consumes 2.3 mW from a single 2-V power supply demonstrates a high sensitivity of -72 dBm. It occupies an active area of 0.2 mm/sup 2/ using 0.6-/spl mu/m digital CMOS technology.