CA3089
FM IF System
Not Recommended for New Designs.Contact our Technical Support Center at 1-888-INTERSIL.
Typical Diagram

Key Features
- For FM IF Amplifier Applications in High-Fidelity, Automotive, and Communications Receivers
- Includes: IF Amplifier, Quadrature Detector, AF Preamplifier, and Specific Circuits for AGC, AFC, Muting (Squelch), and Tuning Meter
- Exceptional Limiting Sensitivity at -3dB Point 12µV (Typ)
- Low Distortion: (with Double-Tuned Coil) 0.1% (Typ)
- Single-Coil Tuning Capability
- High Recovered Audio 400mV (Typ)
- Provides Specific Signal for Control of Interchannel Muting (Squelch)
- Provides Specific Signal for Direct Drive of a Tuning Meter
- Provides Delayed AGC Voltage for RF Amplifier
- Provides a Specific Circuit for Flexible AFC
- Internal Supply-Voltage Regulators
Description
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.

