U4270B
U4270B is FM IF limiter amplifier and detector manufactured by TEMIC Semiconductors.
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TELEFUNKEN Semiconductors
U 4270 B
FM IF limiter amplifier and detector
Description
The U 4270 B is an integrated bipolar FM-IF amplifier circuit with field strength indicator, stop signal generator, multipath detector and controllable mute function. It is designed for car radios and home receiver applications.
Features
D 7 stage limiter amplifier D Multipath signal detector D Stop signal generator with controllable threshold D Signal strength output D Controllable mute function D High signal/noise ratio and low signal distortion
Block Diagram
R3
1 14 (15) 9 (10) 10 (11)
Mute depth control
3 (4) 4 (5) 8 (9)
18(20) (19) 17
(8) 7
16 (18)
5 (6)
(7)
11 (12)
15 (16) 13 (14)
12 (13)
( ) SSO 20
94 8876
Rev. A1: 07.10.1994
Preliminary Information
U 4270 B
Pin description
DIP 18 1 2
- 3 4 5 6 7 8 9 10 SSO 20 1 2 3 4 5 6 7 8 9 10 11 Symbol GND MUTE IN NC MUTE DE AF STOP SEN Function Ground Mute input N.C. Mute depth AF output Search tuning stop sensitivity STOP SIG Search stop signal output AFC AFC output RVOLT Reference voltage output DEMOD Demodulator circuit DEMOD Demodulator circuit DIP 18 11 12 13 14 15
- 16 17 18 SSO 20 12 13 14 15 16 17 18 19...
