1997 Nov 21

17

Philips Semiconductors

Product specification

65

× 102 pixels matrix LCD driver

PCF8549

PCF8549 (see Fig.14). The coefficients are selected by the two bits TC[1 : 0]. Table 6 shows the typical values of the

Bias value:

The bias voltage levels are set in the ratio of R

− R − nR − R − R giving a

bias system. The resulting bias levels

are shown in table 5.

Different multiplex rates require different factors n (see Table 4). This is programmed by BS[2 : 0]. For MUX 1 : 65 the

optimum bias value n is given by:

Table 4

Programming the required Bias system

BS[2]

BS[1]

BS[0]

n

b (RES. COUNT)

MUX RATE

0007

11

1 : 100

0016

10

1 : 81

0105

9

1 : 64

0114

8

1 : 49

1003

7

1 : 36

Fig.14 Temperature coefficients.

temperature

1

n4

+

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

nm

3

–

65

3

–

5.06

5

==

=

=