PCF8531USLASH2 datasheet(15/44 Pages) PHILIPS

15 / 44 page

2000 Feb 11

Philips Semiconductors

Product speciﬁcation

× 128 pixel matrix driver

PCF8531

handbook, full pagewidth

MGL935

VLCD

. . . 7D

. . . 5F

LOW

HIGH

Fig.8 VOP programming of PCF8531.

VOP[6:0] (programmed) [00H to 7FH] programme range LOW and HIGH.

8.18.10 VOLTAGE MULTIPLIER CONTROL S[1:0]

The PCF8531 incorporates a software configurable

voltage multiplier. After reset (internal or external), the

voltage multiplier is set to 2

× VDD2. The voltage multiplier

factors are set via the command ‘HV-gen configuration’

(see Tables 4, 5 and 6).

8.18.11 TEMPERATURE COMPENSATION

Due to the temperature dependency of the liquid crystal’s

viscosity, the LCD controlling voltage VLCD should usually

be increased at lower temperatures to maintain optimum

contrast. Figure 9 shows VLCD for high multiplex rates.

Linear temperature compensation is supported in the

PCF8531. The temperature coefficient of VLCD can be

selected from eight values by setting bits TC[2:0]

(see Tables 4, 5 and 6).

handbook, halfpage

MGS473

VLCD

°C

Fig.9

VLCD as a function of liquid crystal

temperature.

PCF8531U/2 Datasheet(PDF) 15 Page - NXP Semiconductors