An integrated FSK Demodulator with Built-In Self-Calibration

Inhalt:
This paper presents a fully-integrated FSK demodulator circuit. It is based on the phase coincidence demodulator principle and employs an injection-locked oscillator as phase shifter. It contains a digital self-calibration circuit and an AFC loop with dead-band. The FSK demodulator was realized in a 0.6 µm BiCMOS process. It uses an IF frequency of 2 MHz and consumes 320 muA from a supply voltage between 1.9 V and 5.5 V. This makes it well suitable for receiver/transceiver ICs targeted at the world-wide license-free ISM/SRD bands.