hd61603r ETC-unknow, hd61603r Datasheet - Page 28

• Manufacturer Part Number: hd61603r
• Description: Segment Type Lcd Driver
• Manufacturer: ETC-unknow

When External Drive Power Supply Is Used
An external power supply can be used by setting external voltage switching bits of mode setting data to 1.
When a large liquid crystal display panel is used, in multichip designs, which need accurate liquid crystal
drive voltage, use the external power supply. See Figure 22.
R2–R5 is connected in series between VDD and VSS, and by these resistance ratio each voltage of ÆV
and VLCD is generated and then supplied to V1, V2, and V3. C2–C4 are smoothing capacitors.
When regulating brightness, change the resistance value by setting R5 variable resistance.
Notes: 1.
Positive
power
supply
SB
Figure 21 Voltage Characteristics between VDD and Vref1
(1) Static Drive
Figure 22 Example when External Drive Voltage Is Used
2.
C4
R2
When standby mode is used, a transistor is required.
R2–R5 should be some k –some tens of k , and C2–C4 should be 0.1 F–0.3 F.
C6
R5
NC
NC
T
r
VDD
VSS
VREF1
VREF2
VC1
VC2
V1
V2
V3
Positive
power
supply
(2) 1/2 Duty Cycle Drive
SB
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
C2
C3
R2
R3
C6
VDD–VSS (V)
R5
2
NC
NC
T
r
3
VDD
VSS
VREF1
VREF2
VC1
VC2
V1
V2
V3
4
5
Positive
power
supply
6
Min
Typ
Max
(3) 1/3 and 1/4 Duty Cycle Drive
SB
C2
C3
C4
R2
C6
R3
R4
R5
NC
NC
T
r
HD61602/HD61603
VDD
VSS
VREF1
VREF2
VC1
VC2
V1
V2
V3
C6
1 F
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