LV25700PM Datasheet, PDF (21/68 Pages) Sanyo Semicon Device – For Car Radio Single chip Tuner IC

LV25700PM
Continued from preceding page.
Pin name
Function
73 AM/FM 1st IF
MIXER AMP output
Discription
Output impedance = 330Ω
Internal Equivalent Circuit
RF_VCC(PIN2)
50Ω
73
300Ω
74
IF VCC
(IF)
75 AM/FM 1st IF MIXER AM/FM 450kHz AMP
76 AMP input
Input impedance = 330Ω
VCC = 5V
75
RF_GND(PIN12)
76
300Ω 300Ω
300Ω
77 AM RF AGC
RF AGC rectifier capacitor
Determination of the distortion ratio during
low-frequency modulation
Increase C77:
Distortion → improved
Response → slow
Decrease C77:
Distortion → worse
Response → quick
* Same as pin 79.
78 HCC control input pin With the Pin 78 input voltage, attenuation of
the high pass component is controlled.
↓
At weak input, high pass is cut to reduce
the noise feeling.
• Same control for FM/AM HCC.
• The f-characteristics are set by changing
over the external capacity (Pin 51) and
internal resistor.
• Threshold can be controlled with 5 bits.
(FM/AM HCC DAC).
79 AM RF AGC
BYPASS
80 MIXER OUT2
RF AGC rectifier capacitor
Determination of the distortion ratio during
low-frequency modulation
Increase C77:
Distortion → improved
Response → slow
Decrease C77:
Distortion → worse
Response → quick
* Same as pin 77.
* See pin 1 description.
IF_GND(PIN12)
RF_VCC(PIN2)
800kΩ
1kΩ
1kΩ
1kΩ
IF_GND(PIN72) ⁷⁷
RF_VCC(PIN2)
50kΩ
1kΩ
50kΩ
BB_GND(PIN48)
78 ^{BB_GND(PIN48)}
30kΩ 1kΩ
IF_GND(PIN72)
79
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