ST7282A5 - ST7282B5 - ROM FROM EPROM

Family

Issuer Ref.

Chrono

March 26, 1997

Previous Ref

Edition

ST7

PG-RO

97115

7282A5B5

Target C

Page 13/23

2.2.2 External Divider Chain

The different display voltage levels are supplied by an external resistor chain as shown in fig. below.

Two different configurations with five or four display voltage levels can be chosen.

The resistors have to have a good matching within < 1% to avoid DC voltage levels on the liquid crystal

device.

DC levels trigger electrode reactions on the liquid crystal cell, deteriorating display quality rapidly.

Figure 3. External Divider Chain

VLCD

VLCD

C4

C3

C2

C1

C3

C2

C1

R5

R4

R3

R2

R1

VLCD45

VLCD35

VLCD25

VLCD15

VLCD45

VLCD35

VLCD25

VLCD15

GND

GND

R4

R3

R2

R1

ST6LCD3 4.DS4