LM3189中文资料FM IF System数据手册TI规格书

描述 Description

General Description
The LM3189N is a monolithic integrated circuit that provides all the functions of a comprehensive FM IF system. The block diagram of the LM3189N includes 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 programmable delayed AGC for the RF tuner, an AFC drive circuit, and an output signal to drive a tuning meter and/or provide stereo switching log ic. In addition, internal power supply regulators maintain a nearly constant current drain over the voltage supply range of a8.5V to a16V.
The LM3189N is ideal for high fidelity operation. Distortion in an LM3189N FM IF system is primarily a function of the phase linearity characteristic of the outboard detector coil.
The LM3189N has all the features of the LM3089N plus additions.
The LM3189N utilizes the 16-lead dual-in-line plastic package and can operate over the ambient temperature range of -40°C to +85°C.

特性 Features

■ Exceptional limiting sensitivity: 12 μV typ at -3 dB point
■ Low distortion: 0.1% typ (with double-tuned coil)
■ Single-coil tuning capability
■ Improved (S + N)/N ratio
■ Externally programmable recovered audio level
■ Provides specific signal for control of inter-channel muting (squelch)
■ Provides specific signal for direct drive of a tuning meter
■ On channel step for search control
■ Provides programmable AGC voltage for RF amplifier
■ Provides a specific circuit for flexible audio output
■ Internal supply voltage regulators
■ Externally programmable ON channel step width, and
   deviation at which muting occurs