Kenwood KCH-19 Service Manual page 4

2.2 COMPONENTS DESCRIPTION
2.2.1 SUB (Display) unit (XC3-0020-20)
Ref.No Part Name
IC1 IC
IC2 IC
IC3 IC
IC4 IC
IC6 IC
IC8 IC
IC9 IC
IC10 IC
IC12 IC
Q2 FET
Q3, 4 Transistor
Q6 Transistor
D1, 2 Zener diode
D4~7 LED
D9~12 LED
D14~16 LED
D20 Zener diode
D21 LED
D22 Diode
D23, 24 Zener diode
D25 Varistor
D26~32 Zener diode
2.3 TERMINAL FUNCTION
2.3.1 Sub (Display) unit (XC3-0020-20)
Pin No. Name I/O
CN2 (to Main unit A/2 CN900 of transceiver)
1 SP+
2 SPG - Speaker ground
3 GND - Ground
4 SB
CN4 (LCD)
1 VSSA - Ground
2 VSSA - Ground
3 VSSA - Ground
4 VCC O 3V output
5 VCC O 3V output
6 VSSD - Ground
7 VSSD - Ground
8 VSSD - Ground
9 IOVCC O 1.8V output
10 IOVCC O 1.8V output
11 RDX O LCD driver RD signal
12 WRX O LCD driver WR signal
1-4 (No.RA019<Rev.001>)
Description
Voltage regulator (50M)
Voltage regulator (30LCD)
Logic control
Analog SW
Illuminance sensor
LED driver
Logic control
I/O expander
Logic control
DC SW
DC SW
DC SW
Overvoltage protection
LED
LED
LED
Overvoltage protection
LED
Overvoltage protection
Overvoltage protection
Surge protector
Overvoltage protection
Function
I Speaker output
I Switched power supply
Pin No. Name I/O
13 DCX O LCD driver data/command switch
14 CSX O LCD driver chip-serect signal
15 DB1 I/O LCD driver data output
16 DB2 I/O LCD driver data output
17 DB3 I/O LCD driver data output
18 DB4 I/O LCD driver data output
19 DB5 I/O LCD driver data output
20 DB6 I/O LCD driver data output
21 DB7 I/O LCD driver data output
22 DB8 I/O LCD driver data output
23 DB10 I/O LCD driver data output
24 DB11 I/O LCD driver data output
25 DB12 I/O LCD driver data output
26 DB13 I/O LCD driver data output
27 DB14 I/O LCD driver data output
28 DB15 I/O LCD driver data output
29 DB16 I/O LCD driver data output
30 DB17 I/O LCD driver data output
31 CABC - No connection
32 RESX O LCD driver reset signal
33 IM0 O Interface mode select
34 LEDA O 54M output (LED light anode)
35 LED1 I LED light cathode 1
36 LED2 I LED light cathode 2
37 LED3 I LED light cathode 3
38 LED4 - No connection
CN5 (Internal speaker)
1 SPG - Speaker ground
2 SP+ O Speaker output
CN6 (to Main unit A/2 CN749 of transceiver)
1 GND - Ground
2 R_SET0 O Radio setting signal 0
3 R_SET1 O Radio setting signal 1
4 R_SET2 O Radio setting signal 2
5 ME - MIC ground
6 MIC O MIC signal output
7 AFO- I AF signal input minus
8 AFO+ I AF signal input plus
9 /PSW O Detection signal input of power
10 /PTT O PTT output
11 TXD I Serial data input
12 RXD O Serial data output
13 GND - Ground
14 DM/KVL I/O MIC data detection
15 33M I 3.3V input
Function
signal
switch