Read Sony ICF-C795RC Service Manual online
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– 18 –
• IC Block Diagrams
– MAIN Board –
– MAIN Board –
IC1
CXA1019M
IC50
BU2614FS
– ANTENNA Board –
IC451
U4226B-MFSG3
VCC
RF IN
GND
3
SB
4
5
6
7
8
9
FLA
FLB
SL
10
1
AGC
AMPLIFIER
POWER
SUPPLY
RECTIFIER &
INTEGRATOR
DECODER
REC
DEC
INT
Q2A
Q2B
Q1A
Q1B
13
12
11
14
TCO
PON
16 15
2
FM IN
PD1
VSS
VDD2
VDD1
AM IN
P2
IF-IN
XOUT
XIN
CE
CK
DA
CD
P0
P1
16
12
13
14
15
8
9
10
11
4
5
6
1
2
3
7
IF
COUNTER
OUTPUT
CONTROL
I/O CONTROL
REGISTER
MAIN CONTROL
PRESCALLER
PHASE
DETECT
•
MAIN BOARD IC100
µ
PD753106GC-064-AB8 (SYSTEM CONTROLLER, LCD DRIVER, KEY CONTROL)
Pin No.
Pin Name
I/O
Description
1
BIAS
O
Liquid crystal display drive bias control output terminal
2 to 4
VLC0 to VLC2
—
Terminal for doubler circuit capacitor connection to develop liquid crystal display drive voltage
5
NC
O
Not used (open)
6
ALM A
O
LED drive signal output of the LCD back light LED (D74)
“H” output at alarm A setting (LED on)
“H” output at alarm A setting (LED on)
7
ALM B
O
LED drive signal output of the LCD back light LED (D75)
“H” output at alarm B setting (LED on)
“H” output at alarm B setting (LED on)
8
KS4
O
Key scan signal output of the key matrix (S101, S201 to S218)
9
VSS
—
Ground terminal
10 to 13
KS0 to KS3
O
Key scan signal output of the key matrix (S101, S201 to S218)
14 to 17
KR0 to KR3
I
Key return signal input of the key matrix (S101, S201 to S218)
18
RESET
I
System reset signal input from the reset signal generator (IC101) “L”: reset
“L” is input for several 100 msec after power on, then it changes to “H”
“L” is input for several 100 msec after power on, then it changes to “H”
19
XT1
I
Sub system clock input terminal (32.768 kHz)
20
XT2
O
Sub system clock output terminal (32.768 kHz)
21
IC
—
Connected to power supply (+3.8V)
22
X1
I
Main system clock input terminal (4.19 MHz)
23
X2
O
Main system clock output terminal (4.19 MHz)
24
VDD
—
Power supply terminal (+3.8V)
25
DATA IN
I
Time code data input from the U4226B (IC451)
26
CLK
O
PLL serial data transfer clock signal output to the FM/AM PLL (IC50)
27
DATA
O
PLL serial data output to the FM/AM PLL (IC50)
28
PDET
I
Power failure detection input terminal “L”: power failure
29 to 31
PI0 to PI2
I
Destination setting terminal
32
TEST
I
Test mode input terminal “L”: test mode Not used (open)
33
MUTE
O
Muting on/off control signal output terminal “L”: muting on
34
CE
O
PLL serial chip enable signal output to the FM/AM PLL (IC50)
35
BZ-CTRL
O
Buzzer control signal output terminal “H” output at alarm B active
36
BUZZER
O
Beep sound (2 kHz) drive signal output to the CXA1019M (IC1)
37 to 60
S23 to S0
O
Segment drive signal output to the liquid crystal display (LCD100)
61 to 64
COM0 to COM3
O
Common drive signal output to the liquid crystal display (LCD100)
4-4.
IC PIN FUNCTION DESCRIPTION
FM FE
TUNING METER
AM IF DET AGC
AF POWER AMP
FM IF
FM/AM
IF OUT
FM RF IN
FE GND
NC
AM RF IN
FM RF
FM OSC
REG OUT
AFC
AM OSC
NF
VOL
FM DISCRI
GND
FM/AM BAND
SELECT
FM IF IN
AM IF IN
NC
METER
IF GND
DET OUT
AFC AGC
AFC AGC
AF IN
RIPPLE FILTER
AF OUT
VCC
GND
AM FE
FM
DISCRIMINATOR
14
13
11
9
8
7
2
1
6
5
3
4
15
16
17
18
19
20
21
22
23
24
25
26
27
28
12
10
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