HD66420 Datasheet, PDF (40/52 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

HD66420
Vcc ^VLCD
IREFP
r
IV1
GND
R4
r
IV2
Resister for
bias current
of operational
amplifier
IREFM
IV3
r
IV4
Operational
amplifier OFF
- ^R1
+
VLCD
C1
V1O
- ^R1
+
C1
V2O
Bias
- ^{R3 control}
+
C1
V3O
- ^R1
+
C1
V4O
External voltage
booster
Vout
on/off
r
IV5
- ^R1
+
resistive divider for
partial display mode
Contrast ^R2
control
circuit
HD66420
C1
V5O
GREF
DCON
R1 = R
R2 = 0.0625R to 2R
R3 = 2R to 5R
R4 = 1MΩ to 5MΩ
C1 = 1µF to 3µF
Figure 24 Power Supply Circuit
40