HD66760 Datasheet, PDF (77/105 Pages) Hitachi Semiconductor – 104 X 80-dot Graphics LCD Controller/Driver for 256 Colors

HD66760
Switching the Step-up Factor
Instruction bits (BT1/0 bits) can optionally select the step-up factor of the internal step-up circuit. According
to the display status, power consumption can be reduced by changing the LCD drive duty and the LCD drive
bias, and by controlling the step-up factor for the minimum requirements. For details, see the Partial-display-
on Function section.
According to the maximum step-up factor, external capacitors need to be connected. For example, when the
maximum step-up is five times, capacitors between C6+ and C6– or between C5+ and C5– are needed as in
the case of the six-times step-up.
Place a capacitor with a breakdown voltage of three times or more the Vci-GND voltage between C6+ and
C6– and between C3+ and C3–, a capacitor with a breakdown voltage larger than the Vci-GND voltage
between C1+ and C1–, C2+ and C2–, C4+ and C4–, and C5+ and C5–, and a capacitor with a breakdown
voltage of n times or more the Vci-GND voltage to VLOUT (n: step-up factor) (see figure 53).
Note: Determine the capacitor breakdown voltages by checking Vci voltage fluctuation.
Table 37 VLOUT Output Status
BT1
BT0
VLOUT Output Status
0
0
Three-times step-up output
0
1
Four-times step-up output
1
0
Five-times step-up output
1
1
Six-times step-up output