337
chip power supply circuit, or by using an external circuit. With the H8/3867 Series, the
on-chip power supply circuit allows the selection of either the power supply voltage (V
CC
)
or a step-up constant voltage (5 V). For details of the step-up constant-voltage power
supply, see 13.3.4, Step-Up Constant-Voltage (5 V) Power Supply.
When the on-chip power supply circuit is used for the LCD drive power supply, the V
0
and
V
1
pins should be interconnected externally, as shown in figure 13.4 (a).
When an external power supply circuit is used for the LCD drive power supply, connect
the external power supply to the V
1
pin, and short the V
0
pin to V
CC
externally, as shown
in figure 13.4 (b).
Figure 13-4 Examples of LCD Power Supply Pin Connections
e. Low-power-consumption LCD drive system
Use of a low-power-consumption LCD drive system enables the power consumption
required for LCD drive to be optimized. For details, see 13.3.5, Low-Power-Consumption
LCD Drive System.
f.
Segment external expansion
The number of segments can be increased by connecting an HD66100 externally. For
details, see section 13.3.8, Connection to HD66100.
V
CC
V
1
V
2
V
3
V
SS
V
0
(a) Using on-chip power supply circuit
V
CC
V
1
V
2
V
3
V
SS
V
0
(b) Using external power supply circuit
External power supply