Kenwood TK-390 Service Manual page 26

4. DC-DC Converter : MAX865 (TX-RX Unit IC4)
4-1. Terminal connection
3.3µF
1
+
C1– C1+
2
+
C2+ V+
3.3µF 3
C2– IN
4
V– GND
4-3. Electrical characteristics
Parameter
Minimum supply voltage
Maximum supply voltage
Supply current
Oscillator frequency
Note 1 : These specifications are guaranteed by design and are not production tested.
5. LCD Driver : LC75824W (Control unit IC101)
5-1. Block diagram
VDD1
Common
driver
VDD2
INH
Clock
OSC
Generator
VDD
VSS
SEMICONDUCTOR DATA
8
V
IN
7
OUT+
3.3µF
I +
V
6 +
R +
L
5
+
I –
V
R –
L
OUT–
Conditions
R =10kΩ
LOAD
R =10kΩ
LOAD
T =+25°C
A
T =–40°C to +85°C (Note 1)
A
T =+25°C
A
T =–40°C to +85°C (Note 1)
A
................... ........
Segment Driver & Latch
Shift Register
Address
Detector
4-2. Terminal description
Pin No. Name
1 C1– Negative terminal of the flying boost capacitor.
2 C2+ Positive terminal of the flying inverting capacitor.
3 C2– Negative terminal of the flying inverting capacitor.
4 V– Output of the inverting charge pump.
5 GND Ground
6 IN Positive power supply input
7 V+ Output of the boost charge pump.
8 C1+ Positive terminal of the flying boost capacitor.
MIN TYP MAX Units
2.0 1.5 V
6.0 V
0.6 1.05 mA
1.15
19.5 24 32.5 kHz
18 34
5-2. Terminal function
Pin No. Name I/O Active
1~12 S1/P1~S12/P12 O
13~51 S13~S51
52~55 COM1~COM4 O
56 VDD –
57 VDD1 I
58 VDD2 I
59 VSS –
60 OSC I/O
61 INH I
62 CE I
63 CL I
64 DI I
TK-390
Function
Function
– Segment output for displaying
data transferred from serial data.
– Common driver output.
Frame frequency fo=(fosc/512)Hz
–
– 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.
–
– Oscillation terminal.
L Force the display to turn off
regardless of internal data. Serial
data can be input regardless of
whether it is "H" or "L".
H Chip enable. Serial data transfer
terminal. Connected to the
microprocessor.
↑
Synchronizing clock. Serial data
transfer terminal. Connected to
the microprocessor.
– Transfer data. Serial data transfer
terminal. Connected to the
microprocessor.
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