Kenwood TK-260N Service Manual page 23

TK-260G/(N)/270G/(N)
CIRCUIT DESCRIPTION/SEMICONDUCTOR DATA
8. CONTROL SYSTEM
Keys and channel selector circuit.
The signal from the keys and channel selector are directly
input to the microprocessor, as shown in fig. 10.
Channel selector
25
EN1
16
EN2
27 EN3
TK-260G
CN1
CN501
TK-270G
Fig. 10 Control system
SEMICONDUCTOR DATA
LCD Driver : LC75823W (Display UNIT IC501)
(TK-270G only)
Block diagram
COM1 COM2 COM3
V 1
COMMON
DD
DRIVER
V 2
DD
INH
CLOCK
OSC
GENERATOR
Pin function
Pin No. Name I/O Active
1-52 S1-S52 O -
53-55 COM1-COM3 O -
56 VDD - -
57 INH I L
58 VDD1 I -
59 VDD2 I -
22
5M
3
PTT
PTT
47k
SW
87
KEYAD
47k
IC13
-COM
100k
1 2 3 A
4 5 6 B
8
7 9 C
∗
0 # D
S52 S51 S1
LATCH & DRIVER
SHIFT REGISTER
ADDRESS
DETECTOR
DI CL CE V V
DD SS
Function
Segment output for displaying data
transferred form serial data.
Common drive output.
Frame frequency fo=(fosc/384)Hz
The display to turn off
INT=L : Turn off
INT=H : Turn on
Apply 2/3 the LCD drive bias voltage
from outside. If 1/2 the bias is applied,
connect to VDD2.
Apply 1/3 the LCD drive bias voltage
from outside. If 1/2 the bias is applied,
connect to VDD1.
Pin No. Name I/O Active
60 VSS -
61 OSC I/O
62 CE I
63 CL I
64 DI I
LAMP
SW
UPB1509GV (IC301)
MONI
SW
Pin connection diagram
1 5
2 6
3 7
4 8
Block diagram
IN
IN
Pin Function
Pin Pin Applied Pin
No. name voltage voltage
1 V 2.2-2.5
CC1
2 IN - 1.7-4.95 Signal input pin. Connect a coupling capacitor to this pin for
3 IN - 1.7-4.95 Input signal bypass pin. Connect a bypass capacitor to this
4 GND 0
5 SW1 H/L
6 SW2
7 OUT - 1.0-4.7 Division signal output pin. Emitter follower output. 0.1 Vpf or
8 V 2.2-5.5
CC2
Function
-
- Oscillation terminal
Chip enable. Serial data transfer terminal.
H
Connected to the microprocessor.
Synchronizing clock. Serial data transfer terminal.
Connected to the microprocessor.
Transfer data. Serial data transfer terminal.
-
Connected to the microprocessor.
Pin No.
1
2
3
4
5
6
7
8
D Q D Q D Q
CLK CLK CLK
Q Q Q
SW1 SW2
Functions and uses
- Power supply voltage pin for the input amplifier section and
division circuit. Connect a bypass capacitor to this pin to reduce
the high-frequency impedance with the ground (for example, 1000 pF).
DC cutting with an external circuit (for example, 1000 pF).
pin to reduce the high-frequency impedance with the ground
(for example, 1000 pF).
- Ground pin. Connect it with the ground pattern. The ground
pattern on the PC board should be wide enough to minimize
impedance.
- Division ratio setting pin. The division ratio can be set by the
following voltage:
H
SW1
L
Connect a bypass capacitor to this pin to reduce the high-
frequency impedance with the ground.
more can be output under 200-ohmload. Connect a coupling
capacitor to this pin for DC cutting with an external circuit
(for example,1000 pF).
- Power supply voltage pin for the output buffer circuit. Connect
a bypass capacitor to this pin to reduce the high-frequency
impedance with the ground (for example, 1000 pF).
Pin Name
V
CC1
IN
IN
GND
SW1
SW2
OUT
V
CC2
OUT
SW2
H L
1/2 1/4
1/4 1/2