pcf85134 NXP Semiconductors, pcf85134 Datasheet - Page 8

• Manufacturer Part Number: pcf85134
• Description: Universal Lcd Driver For Low Multiplex Rates
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF85134_1
Product data sheet
V
D
where the values for n are
The RMS off-state voltage (V
Discrimination is the ratio of V
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
2
2
off RMS
•
•
n = 1 for static drive mode
n = 2 for 1:2 multiplex drive mode
n = 3 for 1:3 multiplex drive mode
n = 4 for 1:4 multiplex drive mode
=
bias is
bias is
1:3 multiplex (
1:4 multiplex (
----------------------- -
V
V
Equation
off RMS
on RMS
=
----------
3
3
21
V
LCD
=
=
=
3, the discrimination for an LCD drive mode of 1:3 multiplex with
1.732
----------------------------- -
n
1.528
1
1
a
2
2
2
------------------------------------------- -
a
a 1
V
–
bias):
bias):
Rev. 01 — 17 December 2009
1
+
2a
–
LCD
and the discrimination for an LCD drive mode of 1:4 multiplex with
+
.
1
LCD
+
a
2
2
V
V
n
=
+
2
+
LCD
is sometimes referred as the LCD operating voltage.
LCD
off(RMS)
on(RMS)
3V
n 1
n 1
–
–
off RMS
=
=
) for the LCD is calculated with
--------------------- -
6 V
to V
4
3
off(RMS)
when
Universal LCD driver for low multiplex rates
off RMS
3
=
1
and is determined from
3
2.309V
bias is used.
=
2.449V
off RMS
off RMS
Equation
PCF85134
© NXP B.V. 2009. All rights reserved.
Equation
2:
3:
8 of 40
LCD
(2)
(3)