ST7522 Sitronix, ST7522 Datasheet - Page 30

• Manufacturer Part Number: ST7522
• Description: 17 x 96 Dot Matrix LCD Controller
• Manufacturer: Sitronix

The value of Vref is not allowed to be lower than
1.2V within the contrast adjustment range.
[
[3FH-EC volume] x 20KΩ=REC
ST7522
The V5 level be generate by OPAmp with VDD-Vcap3 power supply, so that V5 level must to be smaller than Vcap3 over –0.5V.
Fine adjustment must to used EC[5:0] adjust of Electronic contrast set command.
Coarse adjustment must to used jvref[1:0] adjust of Follower input voltage set command.
For V5 voltage level setup formula:
(follower must on of power control command)
(used follower input voltage set and amplified ratio command)
Ver 1.0c
Jvref[1,0]
[
1M+R
Rvref
1M+R
Rvref
Rvref
7
6
5
4
3
2
1
0
EC
EC
Reference voltage jvref[1:0]
200K
[1,1]
] x V5 amp ratio x (V
Electric volumn EC[5:0]
] x (V
(default)
400K
[1,0]
SS-
V
DD)
Contrast[5,0]
600K
[0,1]
=V
ref
800K
SS-
[0,0]
V
V
DD
SS
V
DD
) =V5(±5% range)
V
ref
30/45
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Rarb2
V
V
DD
0
0
0
0
1
1
1
1
cap3
Rarb1
0
0
1
1
0
0
1
1
V5
V4
V3
V2
V1
V
RaRb[2:0]
DD
Rarb0 V5 amplified ratio
0
1
0
1
0
1
0
1
Test condition:
1.
2.
3.
4.
F
(power control command)
5(default)
VDD=3.0V
Booster/Follower=Default set
Bias=1/6
Only master chip
2.5
3.5
4.5
5.5
2
3
4
V5
2002/07/10
Datasheet pdf - http://www.DataSheet4U.net/