Intersil CA3089 is a monolithic integrated circuit that provides
all the functions of a comprehensive FM-IF system.
The block diagram shows the CA3089 features, which
include a three-stage FM-IF amplifier/limiter configuration
with level detectors for each stage, a doubly-balanced
quadrature FM detector and an audio amplifier that features
the optional use of a muting (squelch) circuit.
The advanced circuit design of the IF system includes desirable
deluxe features such as delayed AGC for the RF tuner,
and AFC drive circuit, and an output signal to drive a tuning
meter and/or provide stereo switching logic. In addition, internal
power supply regulators maintain a nearly constant current
drain over the voltage supply range of +8.5V to +16V.
The CA3089 is ideal for high-fidelity operation. Distortion in a
CA3089 FM-IF System is primarily a function of the phase
linearity characteristic of the outboard detector coil.