LA1781M_09 Datasheet, PDF (14/48 Pages) Sanyo Semicon Device – For Car Radios Single-Chip Tuner IC

Continued from preceding page.
Pin No.
Pin function
44
IF AGC
45
IF output
LA1781M
Pin description
G1 ; Used for time constant switching
during seeks.
• Reception
τ = 2.2μF × 300kΩ
• Seek
τ = 2.2μF × 10Ω
The external capacitors are
connected to VCC.
This is because the IF amplifier
operates referenced to VCC.
The IF amplifier load
Equivalent circuit
0.022μF
+
240kΩ
VCC
C
2.2μF
42
44
VCC
DET
50kΩ
G1
SEEK
ON
10Ω
50kΩ
IF
AGC
Pin 40 VCC
45
Pin 40 VCC
DET
46
AM antenna damping
drive output
Wide band AGC input
I46 = 6mA (maximum)
This is the antenna damping
current.
47
FM muting on level adjustment Modify the value of the external
resistor to adjust the muting on level.
VCC
50pF
46
100Ω
20kΩ
VCC
W.AGC AMP.
ANT DAMPING
DRIVER
VCC
30kΩ
R
47
140μA
Pin 24
Inverter
MUTE
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