Manualshelf

Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller QFN 64 (7x7) 8-Bit 16 MHz I/O number 54
231232233234235236237238239240
239
8018P–AVR–08/10
ATmega169P
23.3.3 1/3 Duty and 1/3 Bias
1/3 bias is usually recommended for LCD with three common terminals (1/3 duty). Waveform is
shown in Figure 23-5. SEG0 - COM0 is the voltage across a segment that is on and SEG0-
COM1 is the voltage across a segment that is off.
Figure 23-5. Driving a LCD with Three Common Terminals
23.3.4 1/4 Duty and 1/3 Bias
1/3 bias is optimal for LCD displays with four common terminals (1/4 duty). Waveform is shown
in Figure 23-6. SEG0 - COM0 is the voltage across a segment that is on and SEG0 - COM1 is
the voltage across a segment that is off.
Figure 23-6. Driving a LCD with Four Common Terminals
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
-
1
/
3
V
LCD
-
2
/
3
V
LCD
-V
LCD
SEG0
COM0
SEG0 - COM0
Frame Frame
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
-
1
/
3
V
LCD
-
2
/
3
V
LCD
-V
LCD
SEG0
COM1
SEG0 - COM1
Frame Frame
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
-
1
/
3
V
LCD
-
2
/
3
V
LCD
-V
LCD
SEG0
COM0
SEG0 - COM0
Frame Frame
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
V
LCD
2
/
3
V
LCD
1
/
3
V
LCD
GND
-
1
/
3
V
LCD
-
2
/
3
V
LCD
-V
LCD
SEG0
COM1
SEG0 - COM1
Frame Frame