HD66740 Datasheet, PDF (47/95 Pages) Hitachi Semiconductor – 112 x 80-dot Graphics LCD Controller/Driver

HD66740
OPOFF = GND
VLCD
VR
V1OUT
R
V2OUT
GND
R0
V3OUT
R
0.1 µF
to 0.5 µF
V4OUT
R
V5OUT
++ +++
R
GND
HD66740
+-
V1
+-
V2
LCD
driver
+-
V3
+
-
V4
+
-
V5
GND
SEG1 to SEG112
COM1 to COM80
Vci
Vci
C1+
+
1 µF
C1-
C2+
+
1 µF
C2-
Booster
1 µF ⁺
+
1 µF
+
1 µF
C3+
C3-
C3+
C3-
VLOUT
GND
Notes: 1. The reference voltage input (Vci) must be adjusted so that the output voltage after boosting will not exceed
the absolute maximum rating for the liquid-crystal power supply voltage (17 V). Particularly, Vci must be
3.3 V or less for five-times boosting.
2. Vci is both a reference voltage and power supply for the booster; connect it to Vcc directly or combine it
with a transistor so that sufficient current can be obtained.
3. Polarized capacitors must be connected correctly.
4. Circuits for temperature compensation should be based on the sample circuit in figure 24.
Figure 23 Internal Booster for LCD Drive Voltage Generation
HD66740
Vcc
Vcc
Thermistor
Vci
Tr
GND
Figure 24 Temperature Compensation Circuit
47