LA1787M Datasheet, PDF (18/54 Pages) Sanyo Semicon Device – Single-Chip Tuner IC for Car Radios

Continued from preceding page.
Pin No.
Function
59
60
Mixer output
63
64
Mixer input
LA1787M
Description
Double balanced mixer
Pins 59 and 60 are the mixer
10.7-MHz output
Pins 63 and 64 are the mixer
input.
This is an emitter insertion type
circuit, and the amount of
insertion is determined by the
capacitors C1 and C2.
Note:The lines for pins 63 and 64
must be kept separated from
the lines for pins 59 and 60.
1ST.IF
Equivalent circuit
OSC
59
60
30Ω
VCC
C1
63
5pF
RF AMP ^C2
64
5pF
620Ω
VCC
620Ω
6
Front end V_CC AM/FM
switching
Pin 6 functions both as the FM
front end V_CC and the AM/FM
switching circuit.
V6 voltage Mode
When 8 V → FM
OPEN → AM
62
1st MIX
INPUT
First mixer input
The input impedance is about
10 kΩ.
A13593
SD
+
8V
VCC
6
510Ω
FM.F.E
AGC 100kΩ
AM/FM
switching circuit
3.3V
3
GND
A13594
to RF
Amp.
62
AM 1st
MIX
10kΩ
2.1V
10
AM 2nd OSC
Crystal oscillator circuit
The Kinseki, Ltd. HC-49/U-S and
a C_L of 20 pF must be used.
10kΩ
5.6V
20pF
33pF
10
X tal
A13595
to 2nd
MIX
A13596
No. 6655-18/54