Fig. 14.3 State When Internal Split Resistors Used; Fig. 14.4 Brightness Adjustment When Internal Split Resistors Used - Fujitsu MB90420/5 (A) Series Hardware Manual

„
Use of internal split resistors
Even when internal split resistors are used, connect an external resistor between Vcc and V
gives the state when internal split resistors are used.
When setting 1/2 bias, short-circuit the V2 pin and V1 pin.
LCD controller
enabled
V
0
„
Brightness adjustment when internal split resistors used
When the brightness does not increase by using internal split resistors, connect an external VR (variable
resistor) between Vcc and V3 and adjust the voltage of the V3 pin.
V to V : Voltages of V0 to V3 pins
0 3

Fig. 14.4 Brightness Adjustment when Internal Split Resistors Used

LCD CONTROLLER/DRIVER
V
3
R
V
2
R
V
1
R
V
0
Q1
1/2 bias
to V : Voltages of V0 to V3 pins
3

Fig. 14.3 State when Internal Split Resistors Used

V
3
V
2
V
1
V
0
LCD controller
enabled
To adjust brightness
V
CC
VR
V
3
V
3
V
V
2
2
Short-
circuited
V
1
V
1
V
V
0 0
LCD controller
enabled
1/3 bias
V
CC
V
3
R
V
2
R
V
1
R
V
0
Q1
14-7
3
V
CC
VR
V
3
R
V
2
R
V
1
R
V
0
Q1
VR
. Figure 14.3