BA4237L

The BA4237L is an AM/FM IF system IC that features a selectable normal or inverted-S FM output characteristic.The FM circuit consists of a differential IF amplifier,a double-balance quardrature detector and a weak signal IF mute circuit.The AM circuit consists of a local oscillator,a double-balanced mixer circuit,an IF amplifier,a detector circuit and an AGC circuit.The IC also has a built-in LED driver circuit for AM/FM tuning LED.It is designed for AM/FM radio-cassette players and home stereo systems.

There are some features BA4237L  as follows.First is wide operating voltage range (2.7 V to 12 V).The second is shunt AGC for improved strong-signal AM input characteristics.Then is built-in FM weak-input muting to reduce noise between stations when tuning and side peaks.This mute circuit can be switched on and off externally.Next is built-in driver circuit for direct drive of AM/FM tuning indicator LED.The fifth is one input for both AM and FM which allows connection to the following stage (eg. MPX) without a switch.The sixth is pin provided for setting AM frequency characteristics.FM and AM frequency characteristics can be assigned independently to facilitate connection to MPX circuits.The last one is switch between AM and FM bands by switching the DC power on and off.

What comes next is about the BA4237L  absolute maximum ratings (T_a=25).The V_CC (supply voltage) is 16 V.The P_d (power dissipation) is 550 mW.The T_opr (operating temperature range) is from -25 to 75.The T_stg (storage temperature range) is from -55 to +125.Then is about the recommended operating conditions (T_a=25).The minimum V_CC (supply voltage) is 2.7 V,the typical is 6 V and the maximum is 12 V.