LC75808W
www.onsemi.com
31
Sample Application Circuit 1
1/8 duty, 1/4 bias drive technique (for use with normal panels)
Note: *6. Add a capacitor to the logic block power supply line so that the logic block power supply voltage V
DD
rise
time when power is applied and the logic block power supply voltage V
DD
fall time when power drops are
both at least 1ms, as the LC75808W is reset by the V
DET
.
*7. If a variable resistor is not used for display contrast fine adjustment, the V
LCD
4 pin must be connected to
ground.
*8. If the function of the INH
pin is not used, the INH pin must be connected to the logic block power supply
V
DD
.
*9. The DO pin, being an open-drain output, requires a pull-up resistor. Select a resistance (between 1 k to 10
k) appropriate for the capacitance of the external wiring so that signal waveforms are not degraded.
COM1
COM2
COM3
COM4
COM5
COM6
COM7
COM8
COM9 OPEN
OPEN
COM10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S56
S57
S58
S59
S60
P1
P2
P3
P4
OPEN
CCC
*6
OSC
INH *8
*9
CE
CL
DI
DO
K
I
5
K
I
4
K
I
3
K
I
2
K
I
1
K
S
6
K
S
5
K
S
4
K
S
3
K
S
2
K
S
1
LCD panel
Used with the backlight
controller or other circuit.
general-purpose output ports
Key matrix
(up to 30 keys)
A12922
+5V
+8V
C0.047F
From the controller
To the controller
To the controller
power supply
V
DD
TEST
V
SS
V
LCD
V
LCD
0
V
LCD
1
V
LCD
2
V
LCD
3
V
LCD
4 *7
