LA1787M Datasheet, PDF (16/54 Pages) Sanyo Semicon Device – Single-Chip Tuner IC for Car Radios

Continued from preceding page.
Pin No.
Function
47
FM muting on level
adjustment
48
RF AGC bypass
57
RF AGC
50
IF bypass
51
FM IF input
52
IF input
LA1787M
Description
Modify the value of the external
resistor to adjust the muting on
level.
Equivalent circuit
30kΩ
VCC
R
47
140µA
Pin 24
VCC
5.6V
RF AGC rectification capacitor
The low frequency distortion is
determined as follows:
Increasing C48 and C57 improves
the distortion but makes the
response slower.
Reducing C48 and C57
aggravates the distortion but
makes the response faster.
48
+
3.3µF
For AGC use
57
+
47µF
Inverter
MUTE
A13586
10kΩ
Antenna
damping
A13587
Due to the high gain of the limiter
amplifer, care must be taken when
choosing the grounding point for
the limiter amplifer input capacitor
to prevent oscillation.
The input impedance is 2 kΩ.
2.6V
10kΩ
50
0.022µF
330Ω
51
10kΩ
IF in
52
2kΩ
A13588
100Ω
A13589
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