pca85232 NXP Semiconductors, pca85232 Datasheet - Page 9

• Manufacturer Part Number: pca85232
• Description: Pca85232 Lcd Driver For Low Multiplex Rates
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA85232
Product data sheet
7.3.1 Electro-optical performance
Using
1
1
The advantage of these LCD drive modes is a reduction of the LCD full scale voltage V
as follows:
These compare with
It should be noted that V
Suitable values for V
RMS voltage, at which a pixel will be switched on or off, determine the transmissibility of
the pixel.
For any given liquid, there are two threshold values defined. One point is at 10 % relative
transmission (at V
For a good contrast performance, the following rules should be followed:
V
of a, n (see
V
manufacturer.
It is important to match the module properties to those of the driver in order to achieve
optimum performance.
V
V
⁄
⁄
2
2
on(RMS)
low
•
•
on RMS
off RMS
bias is
bias is
(
(
1:3 multiplex (
1:4 multiplex (
and V
Equation
)
)
and V
≥
≤
----------
high
V
V
3
3
21
Equation 1
high
low
=
are properties of the LCD liquid and can be provided by the module
off(RMS)
=
All information provided in this document is subject to legal disclaimers.
3, the discrimination for an LCD drive mode of 1:3 multiplex with
1.732
1.528
1
1
low
⁄
⁄
2
2
) and the other at 90% relative transmission (at V
on(RMS)
bias):
bias):
V
Rev. 1 — 8 December 2010
are properties of the display driver and are affected by the selection
LCD
and the discrimination for an LCD drive mode of 1:4 multiplex with
to
.
LCD
Equation
V
V
=
and V
is sometimes referred as the LCD operating voltage.
LCD
LCD
3V
off RMS
=
=
off(RMS)
(
3) and the V
(
--------------------- -
6
4
×
)
×
3
V
are dependant on the LCD liquid used. The
when
off RMS
3
)
(
1
=
LCD
⁄
3
)
2.309V
bias is used.
=
voltage.
LCD driver for low multiplex rates
2.449V
off RMS
(
off RMS
(
)
PCA85232
)
high
© NXP B.V. 2010. All rights reserved.
), see
Figure
9 of 54
LCD
5.
(4)
(5)