353
13.3.7
Boosting the LCD Drive Power Supply
When a large panel is driven, the on-chip power supply capacity may be insufficient. If the power
supply capacity is insufficient when using the step-up constant power supply (5 V), either use V
CC
as the power supply or use an external power supply circuit. If the power supply capacity is
insufficient when V
CC
is used as the power supply, the power supply impedance must be reduced.
This can be done by connecting bypass capacitors of around 0.1 to 0.3 µF to pins V
1
to V
3
, as
shown in figure 13-17, or by adding a split-resistance externally.
Figure 13-17 Connection of External Split-Resistance
H8/3864 Series
V
CC
V
SS
V
1
V
2
V
3
R
R
R
R = several k
Ω
to
several M
Ω
C= 0.1 to 0.3
µ
F
V
0