PCF2119X_10 Datasheet, PDF (10/83 Pages) NXP Semiconductors – LCD controllers/drivers Single-chip LCD controller and driver

NXP Semiconductors
PCF2119x
LCD controllers/drivers
8.4 LCD supply voltage generator
The LCD supply voltage may be generated on-chip. The V_LCD generator is controlled by
two internal 6-bit registers: V_A and V_B. Register V_A is programmed with the voltage for
character mode and register V_B with the voltage for icon mode.
The nominal LCD operating voltage at room temperature is given by Equation 2:
V_LCD(nom) = V_x × 0.08 + 1.82
(2)
Where V_x is the integer value of the register V_A or V_B.
It should be noted that V_LCD is sometimes referred as the LCD operating voltage (V_oper).
8.4.1 Programming ranges
Possible values for V_A and V_B are between 0 to 63.
Table 5. Values of V_A and V_B and the corresponding V_LCD values
All values at T_ref = 27 °C; allowed values are highlighted.
Integer values Corresponding
of V_A and V_B value of V_LCD in V
Integer values Corresponding
of V_A and V_B value of V_LCD in V
0
VLCD switched off 22
3.58
1
1.90
23
3.66
2
1.98
24
3.74
3
2.06
25
3.82
4
2.14
26
3.90
5
2.22
27
3.98
6
2.30
28
4.06
7
2.38
29
4.14
8
2.46
30
4.22
9
2.54
31
4.30
10
2.62
32
4.38
11
2.70
33
4.46
12
2.78
34
4.54
13
2.86
35
4.62
14
2.94
36
4.70
15
3.02
37
4.78
16
3.10
38
4.86
17
3.18
39
4.94
18
3.26
40
5.02
19
3.34
41
5.10
20
3.42
42
5.18
21
3.50
43
5.26
Integer values
of V_A and V_B
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
Corresponding
value of V_LCD in V
5.34
5.42
5.50
5.58
5.66
5.74
5.82
5.90
5.98
6.06
6.14
6.22
6.30
6.38
6.46
6.54
6.62
6.70
6.78
6.86
PCF2119X
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 15 November 2010
© NXP B.V. 2010. All rights reserved.
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