PCF88332DA PHILIPS [NXP Semiconductors], PCF88332DA Datasheet - Page 57

• Manufacturer Part Number: PCF88332DA
• Description: STN RGB - 132 X 132 X 3 driver
• Manufacturer: PHILIPS [NXP Semiconductors]

V
Philips Semiconductors
When the required bias system (a) is defined, the LCD
supply voltage for a display size N can be determined; see
equation (4).
The parameter P in equation (4) is the number of
simultaneous selected rows. For the maximum number of
rows of 132, P = 4 is chosen. When partial Display mode
is selected the P value is set to 1 internally.
The bias voltage levels are a function of the row voltage
F and a:
Depending on the value of p, the bias levels are set in the
ratio of:
p = 1: R
p = 4: R
Where the value of
2003 Feb 14
F
F G
F
------------- -
G
handbook, full pagewidth
LCD
max
F
STN RGB - 132
=
=
V
------------ -
G
---------------------- -
=
max
LCD
=
2
max
2a V
p
a
-- -
p
2R
R
a
ON
R
2R
R
-------------------------------------- -
P a
is in the range from 0 to 4.
R
R
2
V LCD2
+
N
V SS
V2H
V1H
N
V1L
V2L
VC
R
132
Fig.32 Bias levels for a MRA system with P = 4 and P = 1.
+
2a
P = 4
3 driver
F
G max
VC
F
G max
(4)
(5)
(6)
(7)
(8)
57
The bias voltages needed in a MRA LCD driver depends
on the number of simultaneous selected rows (P). The
bias voltages of the PCF8833 are given for P = 4 and
P = 1; see Fig.32. In the PCF8833 the maximum column
voltage (GMAX) is always lower or equal to the row
voltage F.
The value of F is determined by ( + 2)
of G
The relationship between the ratio F/G
or:
The relation between a and
This leads to the following bias systems given in Table 70.
a
------------- -
G
V LCD2
max
F
=
=
V SS
V2H
V2L
VC
max
-- -
------------ - 1
G
2
=
is determined by 2
F
max
+
a
-- -
p
1
=
–
P = 1
---------------------------- -
p
+
2 R
2
2
R
=
F
G max
VC
=
MGU941
G max
F
a
-- - 1
p
----------------- -
R.
–
for a given p is the following:
+
2
2
Objective specification
2
=
max
1
PCF8833
+
R and the value
and
---
2
(10)
(11)
(9)