Internal Generation Mode; External Voltage Application Mode 1; External Voltage Application Mode 2 - Epson S1C17W12 Technical Manual

18 LCD DRIVER (LCD4A)

18.4.1 Internal Generation Mode

This mode generates all the LCD drive voltages V
mode, set both the LCD4PWR.VCEN and LCD4PWR.BSTEN bits to 1 to turn both the LCD voltage regulator and
LCD voltage booster on after setting the LCD4PWR.EXVCSEL bit to 0. Figure 18.4.1.1 shows an external connec-
tion 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 the LCD4PWR.EXVCSEL bit to 1 and set both the LCD4PWR.VCEN and LCD-
4PWR.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, one of the LCD drive voltages V
ternally generated. To put LCD4A into external voltage application mode 2, set the LCD4PWR.EXVCSEL bit to 1,
set the LCD4PWR.VCEN bit to 0 to turn the LCD voltage regulator off, and set the LCD4PWR.BSTEN bit to 1 to
turn the LCD voltage booster on. Figure 18.4.3.1 shows an external connection example for external voltage appli-
cation mode 2.
Figure 18.4.3.1 External Connection Example for External Voltage Application Mode 2 (when V
18-4
to V on the chip. To put LCD4A into internal generation
C1 C3
C
P2
C
LCD4
C
P1
V
C3
V
C2
V
C1
C C
LCD1 LCD2
to V are applied from outside the IC. To put LCD4A into external
C1 C3
C
P2
Open
C
P1
V
C3
R
LCD3
V
C2
R
LCD2
V
C1
R
LCD1
to V are applied from outside the IC and other voltages are in-
C1 C2
C
P2
C
LCD4
C
P1
V
C3
V
C2
V
C1
C
LCD2
Seiko Epson Corporation
C
LCD3
C
LCD3
C1
S1C17W12/W13 TECHNICAL MANUAL
is applied)
(Rev. 1.2)