d. LCD drive power supply setting
With the H8/3887 Series, there are two ways of providing LCD power: by using the on-
chip power supply circuit, or by using an external circuit. When the on-chip power supply
circuit is used, with the H8/3887 Series, either the power supply voltage (VCC) or a step-up
constant voltage (5 V) can be selected. 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 V0 and
V1 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 V1 pin, and short the V0 pin to VCC externally, as shown in
figure 13.4 (b).
V
CC
V
CC
V0
V1
V2
V3
V0
V1
V2
V3
External power supply
VSS
V
SS
(a) Using on-chip power supply circuit
(b) Using external power supply circuit
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. External expansion of segment
Segment can be expanded by externally connecting the HD66100. For details, see 13.3.8,
Connection with HD66100.
354
ETC [ ETC ]
