hd66420 Renesas Electronics Corporation., hd66420 Datasheet - Page 40

• Manufacturer Part Number: hd66420
• Description: Ram-provided 160 Channel 4-level Grey Scale Driver For Dot Matrix Graphics Lcd
• Manufacturer: Renesas Electronics Corporation.

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