Sony BC-1WD Service Manual page 25

S-8054ALR-LN-X (SEIKO I&E)
C-MOS VOLTAGE DETECTOR
—TOP VIEW—
V
DD
2
VOLTAGE
DETECT
1 2 3
OUT V GND
DD
2 1
V OUT
DD
3
GND
GND
3
SN74LS540NS (TI)
TTL OCTAL LINE BUFFERS/DRIVERS WITH 3-STATE OUTPUTS
—TOP VIEW—
V G2 Y1 Y2 Y3 Y4 Y5 Y6
CC
20 19 18 17 16 15 14 13
1 2 3 4 5 6 7 8
A1 A2 A3 A4 A5 A6 A7
G1
2 18
3 17
4 16
5 15
6 14
7 13
8 12
9 11
G1 G2
1 19
TC4081BF (TOSHIBA)
C-MOS 2-INPUT AND GATE
—TOP VIEW—
A
14 13 12 11 10 9 8
B
V
DD
Y = A • B = A + B
GND
1 2 3 4 5 6 7
BC-1WD
1
OUT
Y7 Y8
12 11
A Y
G
G1 G2 A Y
0 0 0 1
0 0 1
0
1 X X HI-Z
9 10 X 1 X HI-Z
A8 GND
0 ; LOW LEVEL
1 ; HIGH LEVEL
X ; DON'T CARE
HI-Z ; HIGH IMPEDANCE
A
Y = Y
B
A B Y
0 0 0
0 1 0
1 0 0
0 : LOW LEVEL
1 1 1
1 : HIGH LEVEL
TC5054P (TOSHIBA)
7-SEGMENT DECODER/DRIVER
—TOP VIEW—
a 1 24 V
CC
b 2 23 BORROW
c 3 22 CARRY
d 4 21 TRF
e 5 20 MR
f 6 19 TEST
g 7 18 UP
T1 DOWN
8 17
T2 9 16 TR
T3 10 15 S
T4 11 14 REXT
GND 12 13 BLC
INPUTS
BLC : BLANKING CONTROL
DOWN : DOWN COUNT
MR : MASTER RESET
REXT : REGISTER EXTERNAL
S : SCAN
TEST : TEST
TR : T-COUNTER RESET
TRF : TRANSFER
UP : UP COUNT
OUTPUTS
a - g : SEGMENT
BORROW : BORROW
CARRY : CARRY
T1 - T4 : DIGIT SELECT
SCAN
15
S
COUNTER
14
REXT
16
TR
13
BLC
21
TRF
A B C D A B C D
19
TEST
LATCH
A1 B1 C1 D1
UP/DOWN
18
U CA1
UP
17
COUNTER
D BO1
DOWN
20
MR
BLANK
CIRCUIT
BCD-TO-7
SEGMENT
DECODER
MULTIPLEXER
A B C D A B C D
LATCH LATCH LATCH
UP/DOWN UP/DOWN
DECADE DECADE
DECADE
COUNTER COUNTER
IC
8 - 11
T1 - T4
1
a
2
b
3
c
4
d
5
e
6
f
7
g
22
CARRY
23
BORROW
5-5