LA1781M_09 Datasheet, PDF (36/48 Pages) Sanyo Semicon Device – For Car Radios Single-Chip Tuner IC

LA1781M
• AM high band cut and detector output level adjustment methods
The pin 31 AM and FM tuner output has an impedance of 10kΩ in AM mode and a few tens of Ohms in FM mode.
Therefore, R31 is used to lower the AM detector output level and C31 determines the AM high band frequency
characteristics.
FM
detector
VCC
31
R31
C31
VCC
+
AM
detector
10kΩ
Noise
canceler
input
30
50kΩ
• AM stereo system pins
VCC
IFT
45
Fig. 39
GND
To the AM stereo decoder
400mVrms
450kHz output
39
IF AMP.
VCC
50pF _150Ω
KEYED AGC
Fig. 40
No.6038-36/48