Lcd Power Supply; Internal Generation Mode - Epson S1C17W14 Technical Manual

18 LCD DRIVER (LCD8B)

18.4 LCD Power Supply

The LCD drive voltages V
lator and LCD voltage booster). One or all voltages can also be applied from outside the IC.

18.4.1 Internal Generation Mode

This mode generates all the LCD drive voltages V
mode, set both the LCD8PWR.VCEN and LCD8PWR.BSTEN bits to 1 to turn both the LCD voltage regulator and
LCD voltage booster on. Figure 18.4.1.1 shows an external connection example for internal generation mode.
Figure 18.4.1.1 External Connection Example for Internal Generation Mode
18.4.2 External Voltage Application Mode 1
In this mode, all the LCD drive voltages V
voltage application mode 1, set both the LCD8PWR.VCEN and LCD8PWR.BSTEN bits to 0 to turn both the LCD
voltage regulator and LCD voltage booster off. Figure 18.4.2.1 shows an external connection example for external
voltage application mode 1.
Figure 18.4.2.1 External Connection Example for External Voltage Application Mode 1 (resistor divider)
18.4.3 External Voltage Application Mode 2
In this mode, the LCD drive voltages V
generated. To put LCD8B into external voltage application mode 2, set the LCD8PWR.VCEN bit to 0 to turn the
LCD voltage regulator off and the LCD8PWR.BSTEN bit to 1 to turn the LCD voltage booster on. Figure 18.4.3.1
shows an external connection example for external voltage application mode 2.
Figure 18.4.3.1 External Connection Example for External Voltage Application Mode 2 (when V
18-4
to V can be generated by the internal LCD power supply circuit (LCD voltage regu-
C1 C3
C1
C
P2
C
P1
V
C3
V
C2
V
C1
to V
C1 C3
C
P2
C
P1
V
C3
V
C2
V
C1
or V is applied from outside the IC and other voltages are internally
C1 C2
C
P2
C
P1
V
C3
V
C2
V
C1
Seiko Epson Corporation
to V on the chip. To put LCD8B into internal generation
C3
C
LCD4
C C C
LCD1 LCD2 LCD3
are applied from outside the IC. To put LCD8B into external
Open
R
LCD3
R
LCD2
R
LCD1
C
LCD4
C C
LCD2 LCD3
is applied)
C1
S1C17W14/W16 TECHNICAL MANUAL
(Rev. 1.2)