LA1143

Ordering number : EN1140D

FM IF System for Car Radios

Monolithic Linear IC

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN

91297HA (KT)/D157KI/2126KI/5085MW/D142KI, TS No.1140-1/5

Overview

The LA1143 is an IF system IC designed for FM car stereo

receivers. It features versatile muting characteristics and

allows receiver designers to realize the muting

performance according to their design concept. Since the

muting characteristics can be varied with a switch or a

semi-fixed resistor, DX-Local switching will be

accomplished with ease.

Functions

• IF amplification/limiter

• Quadrature detector

• AF preamplifier

• AFC output

• Signal meter output

• AGC output

• Muting at detuning

• Muting at small input

Package Dimensions

unit: mm

3006B-DIP16

[LA1143]

SANYO: DIP16

Features

1. Versatile mutings

a) When muting operation is performed under a weak signal strength, an attenuation slope of the audio output against

the input signal strength variations can be set at any given value.

b) Maximum muting attenuation can be selected to be approximately 6 to 40dB.

c) Input signal strength level which actuates the muting circuit can be set freely.

2. High limiting sensitivity (25 dBµ typ. with muting off) provides a good quieting characteristic.

3. High S/N (78dB typ.)

4. Low distortion (0.05% typ.) available, if used with double-tuned circuits.

5. Good AMR (63dB with 6 stages of differential IF amplifiers).

6. Signal meter drive output proportional to the input signal strength in dB (suitable to control multiplex IC LA3373).

8. Delayed AGC output for front end circuit.

Equivalent Circuit Block Diagram