PCF8531U2D NXP [NXP Semiconductors], PCF8531U2D Datasheet - Page 23

• Manufacturer Part Number: PCF8531U2D
• Description: 34 x 128 pixel matrix driver Single-chip LCD controller and driver
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8531
Product data sheet
9.8 LCD bias voltage
9.9 Set V
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
The practical value for V
threshold voltage (V
As the programming range for the internally generated V
maximum allowed V
selecting the temperature compensation, that the V
exceeded under all conditions and including all tolerances.
Symbol
V1
V2
V3
V4
V5
V6
V
LCD
LCD
LCD
can be set by software. The voltage at intersection temperature [V
= V
=
LCD
th
LCD
------------------------------------- -
2
Intermediate LCD bias voltages
is the threshold voltage of the liquid crystal material used.
value
×
1
(T
⎛
⎝
+
ints
1
All information provided in this document is subject to legal disclaimers.
–
) × [1 + TC × (T − T
34
--------- -
LCD
1
th
34
LCD
), typically when the LCD exhibits approximately 10 % contrast.
⎞
⎠
(T
, the user must ensure, while setting the VOP register and
Rev. 6 — 16 May 2011
×
LCD
ints
V
th
) = a + V
is determined by equating V
=
Bias voltage
V
V
n
----------- -
n
n
----------- -
n
----------- -
n
----------- -
n
LCD
SS
+
+
+
+
2
+
1
+
5.30
3
4
2
4
4
4
Table
×
×
×
×
LCD
V
V
V
V
ints
×
LCD
LCD
LCD
LCD
V
)]
th
× b
10. Two overlapping V
Table 10
DD2
LCD
LCD
and V
limit maximum of 9.0 V is never
can be calculated as:
off(RMS)
LCD
and
Example for
V
6
5
2
1
V
DD3
34 x 128 pixel matrix driver
allows values above the
⁄
⁄
⁄
⁄
Figure
7
7
7
7
LCD
SS
× V
× V
× V
× V
LCD
with a defined LCD
voltages and the display
LCD
LCD
LCD
LCD
ranges can be
12). The maximum
PCF8531
LCD
© NXP B.V. 2011. All rights reserved.
1
⁄
7
(T = T
bias
ints
).
ints
23 of 51
)] can