PCF8562TT-2 NXP [NXP Semiconductors], PCF8562TT-2 Datasheet - Page 8

• Manufacturer Part Number: PCF8562TT-2
• Description: Universal LCD driver for low multiplex rates
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8562
Product data sheet
Discrimination is a term which is defined as the ratio of the on and off RMS voltage across
a segment. It can be thought of as a measurement of contrast.
Table 5.
A practical value for V
threshold voltage (V
the static drive mode a suitable choice is V
Multiplex drive modes of 1:3 and 1:4 with
hence the contrast ratios are smaller.
Bias is calculated by
The RMS on-state voltage (V
where the values for n are
The RMS off-state voltage (V
Discrimination is the ratio of V
V
V
D
LCD drive
mode
static
1:2 multiplex 2
1:2 multiplex 2
1:3 multiplex 3
1:4 multiplex 4
on RMS
off RMS
a = 1 for
a = 2 for
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
=


---------------------- -
V
V
off RMS
on RMS




=
=
Biasing characteristics
1
1
⁄
⁄
V
2
3
V
LCD
LCD


Number of:
Backplanes Levels
1
bias
bias
=
All information provided in this document is subject to legal disclaimers.
----------------------------- -
n
----------------------------- -
n
a
a
2


2
a
-------------------------- -
a
th(off)
+
–
2

2

------------ -
1
1
1
LCD
+
2a
–
2a
1
+
+
+
2a
2a
Rev. 6 — 16 June 2011
), typically when the LCD exhibits approximately 10 % contrast. In
a
+
+
a
a
is determined by equating V

+
, where the values for a are
n

+
n
2
3
4
4
4
2
2
n
n
on(RMS)
off(RMS)
on(RMS)
LCD bias
configuration
static
1
1
1
1
) for the LCD is calculated with
⁄
⁄
⁄
⁄
) for the LCD is calculated with
2
3
3
3
to V
off(RMS)
1
Universal LCD driver for low multiplex rates
⁄
LCD
2
bias are possible but the discrimination and
> 3V
and is determined from
th(off)
0
0.354
0.333
0.333
0.333
V
------------------------ -
off RMS
V
off(RMS)
LCD

.

with a defined LCD
1
0.791
0.745
0.638
0.577
V
----------------------- -
on RMS
V

LCD
Equation
Equation
PCF8562

© NXP B.V. 2011. All rights reserved.
Equation

2.236
2.236
1.915
1.732
D
=
2:
1:
------------------------ -
V
V
off RMS
on RMS
3:


8 of 43

(1)
(2)
(3)
