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

摘要

This paper presents a low-voltage low-power IF 455-kHz signalnprocessor that contains a three-stage limiting amplifier and an FM/FSKndemodulator. The limiting amplifier uses an on-chip feedforward offsetncancellation circuit. The FM/FSK demodulator employs a quadraturendetector that is composed of an on-chip phase detector and an externalntank phase shifter. The demodulation constant is 20 mV/kHz with masimumn±10-kHz frequency deviation. The IF signal processor thatnconsumes 2.3 mW from a single 2-V power supply demonstrates a highnsensitivity of -72 dBm. It occupies an active area of 0.2 mm2nusing 0.6-Μm digital CMOS technology