PCF8531U NXP [NXP Semiconductors], PCF8531U Datasheet - Page 21

• Manufacturer Part Number: PCF8531U
• Description: 34 x 128 pixel matrix driver
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8531_4
Product data sheet
9.8 LCD bias voltage
9.9 Set V
Table 8.
Table 9.
V
be calculated as: V
The generated voltage is dependent on the temperature, programmed Temperature
Coefficient (TC) and the programmed voltage at intersection temperature (T
V
The parameter values are given in
selected via the command ‘HV-gen control’ (see
voltage which can be generated depends on the V
load current. For multiplex rate 1:34, the optimum V
Where V
V
BS2
0
0
0
0
1
1
1
1
Symbol
V1
V2
V3
V4
V5
V6
LCD
LCD
LCD
can be set by software. The voltage at intersection temperature [V
= V
=
LCD
th
LCD
------------------------------------- -
BS1
0
0
1
1
0
0
1
1
2
Programming the required bias system
Intermediate LCD bias voltages
is the threshold voltage of the liquid crystal material used.
value
1
(T
+
ints
1
–
)
34
--------- -
LCD
1
34
BS0
0
1
0
1
0
1
0
1
[1 + TC
(T
Rev. 04 — 13 June 2008
ints
V
th
) = a + V
=
Bias voltage
V
V
n
----------- -
n
n
----------- -
n
----------- -
n
----------- -
n
(T
n
7
6
5
4
3
2
1
0
LCD
SS
+
+
+
+
+
+
2
1
5.30 V
3
4
2
4
4
4
Table
T
LCD
V
V
V
V
ints
LCD
LCD
LCD
LCD
)]
Bias system
1
1
1
1
1
1
1
1
th
10. Two overlapping V
11
10
9
8
7
6
5
4
b
Table 10
DD2
LCD
and V
can be calculated as:
and
Comment
recommended for 1:34
recommended for 1:26
recommended for 1:17
recommended for icon mode
Example for
V
6
5
2
1
V
DD3
34 x 128 pixel matrix driver
7
7
7
7
LCD
SS
Figure
LCD
voltages and the display
V
V
V
V
LCD
LCD
LCD
LCD
ranges can be
11). The maximum
PCF8531
LCD
© NXP B.V. 2008. All rights reserved.
1
7
(T = T
bias
ints
).
ints
21 of 44
)] can