Seiko G1216, User Manual, Page: 23 / 27

AN.No.G121600N000-3D0E
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3.5 Contrast Adjustment and Power Supply Example
The LC panel viewing angle and display screen contrast are greatly affected by the ambient
temperature. The recommended LC drive voltage (Vopr) at each temperature is given below. Vopr is
a value at which the best display is visually obtained. This value does not always correspond to the
value at which the best contrast (Cmax.) is obtained. A contrast adjustment circuit example is shown
below
Figure 10 Contrast Adjustment
V
opr
= V
DD
-V
LC
Temperature (
°
C)
Voltage (V
opr
)
-20
13.5
0
13.0
25
12.5
50
11.5
70
10.5
V
DD
V
SS
V
LC
G1216
R
A
C1
C2
12 V
R
A
=10 k
Ω
R
B
=1.2 k
Ω
R
V
(variable resistor)
=10 k
Ω
C1, C2=10
µ
F
R
V
R
B
5V
3.6 MPU Connection Diagram
Figure 11 Example of Connection to Z80A
G1216
D/I
RST
R/W
DB
0
to DB
7
E
CS1
CS2
Z80A
V
DD
V
SS
V
LC
Z80 PIO
Decoder
D0 to D7
A0 to A15
RD
IORQ
M1
INT
φ
RD
IORQ
M1
INT
φ
A0
A1
A / B
C / D
CE
D0 to D7
A0 to A7
B1
B0
B2
B3
B4
B5