HD66750 Datasheet, PDF (56/96 Pages) Hitachi Semiconductor – 128 x 128-dot Graphics LCD Controller/Driver with Four-grayscale Functions

HD66750/1
V cc
Thermistor
HD66750/1
V cc
Tr ^{V ci}
1 µF
(B charac-teristics)
(+)
GND
Thermistor
HD66750/1
V cc
Tr ^{V ci}
GND
(Examp le 1)
GND
(Examp le 2)
Figure 37 Temperature Compensation Circuits
Switching the Boosting Factor
Instruction bits (BT1/0 bits) can optionally select the boosting factor of the internal booster. 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 boosting factor for the minimum requirements. For details, see the Partial-
display-on Function section.
Because of the maximum boosting factor, external capacitors need to be connected. For example, when the
maximum boosting is six times or five times, capacitors between C6+ and C6Ð or between C5+ and C5Ð are
needed as well, as in the case of the seven-times boosting. When the boosting is two-times boosting,
capacitors between C1+ and C1Ð or between C4+ and C4Ð are not needed.
Place a capacitor with a voltage of three times or more the Vci-GND voltage between C6+ and C6Ð and
between C3+ and C3Ð, and a capacitor with a voltage larger than the Vci-GND voltage between C1+ and
C1Ð, C2+ and C2Ð, C4+ and C4Ð, and C5+ and C5Ð.
Place a capacitor with a voltage of N times theVci-GND voltage between VLOUT and GND. (N: boosting
factor)
Note that each capacitors with a voltage should be determined with a voltage fluctuation.
Table 19
BT1
0
0
1
1
VLOUT Output Status
BT0
VLOUT Output Status
0
Two-times boosting output
1
Five-times boosting output
0
Six-times boosting output
1
Seven-times boosting output
56