LA1781M_09 Datasheet, PDF (9/48 Pages) Sanyo Semicon Device – For Car Radios Single-Chip Tuner IC

Continued from preceding page.
Pin No.
Pin function
20
VCO
LA1781M
Pin description
The oscillator frequency is 912Hz.
KBR-912F108
(Kyocera Corporation)
CSB-912JF108
(Murata Mfg. Co., Ltd.)
Equivalent circuit
CSB
912
JF104
20
VREF
10pF
21
PHASE COMP.
22
PHASE COMP.
VREF
15kΩ
+
15kΩ
19kΩ
21
22
23
IF counter buffer seek/stop
switching
This pin functions both as the IF
counter buffer (AC output) and as the
seek/stop switch pin.
The voltage V23 switches between
the following three modes.
During FM reception :
5V : Seek mode
2.5V : Forced SD mode
0V : Reception mode
AM reception
(two modes : 0 and 5V)
5V : Seek mode
0V : Reception mode
4.9V
+
--
SW
+
--
SD circuit
50kΩ
10kΩ
AM MUTE
1.3V _{VCC IF counter}
buffer
150Ω
50F
23
51kΩ
IF
BUFF.
STOP
Forced SEEK
SD:2.5V 5V
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