2000 Nov 22

16

Philips Semiconductors

Product specification

65

× 102 pixels matrix LCD driver

PCF8812

10.8

Bias system

The bias voltage levels are set in the ratio of R -R-nR-R-R giving a

bias system. Different multiplex rates

require different factors ‘n’ (see Table 4). This is programmed by BS2 to BS0. For MUX1 to MUX65 the optimum bias

value ‘n’ is given by:

Table 4

Programming the required bias system

Table 5

LCD bias voltage

BS2

BS1

BS0

n

RECOMMEND MUX

RATE

0007

1 to 100

0016

1 to 80

0105

1 to 65 or 1 to 65

0114

1 to 48

1003

1 to 40 or 1 to 34

1012

1 to 24

1101

1 to 18 or 1 to 16

1110

1 to 10 or 1 to 9

or 1 to 8

SYMBOL

BIAS VOLTAGES

V1

V2

V3

V4

V5

V6

1

n4

+

()

-----------------

n65

3

–

5.062

5

==

=

n3

+

()

n4

+

()

-----------------

n2

+

()

n4

+

()

-----------------

2

n4

+

()

-----------------

1

n4

+

()

-----------------