Datasheet

306
XMEGA B [DATASHEET]
8291B–AVR–01/2013
25.4 Mode of Operation
25.4.1 Static Duty and Static Bias
If all segments on an LCD have one common electrode, then, each segment must have a unique segment terminal. This
kind of display is driven with the waveform shown in Figure 25-3 on page 306. SEG0-COM0 is the voltage across a
segment that is “ON”, and SEG1-COM0 is the voltage across a segment that is “OFF”.
Figure 25-3. Driving an LCD With One Common Terminal
25.4.2 1/2 Duty and 1/3 Bias
For an LCD with two common terminals (1/2 duty) a more complex waveform must be used to individually control
segments. The waveform is shown in Figure 25-4 on page 306. SEG0-COM0 is the voltage across a segment that is
“ON”, and SEG0-COM1 is the voltage across a segment that is “OFF”.
Figure 25-4. Driving an LCD With Two Common Terminals
25.4.3 1/3 Duty and 1/3 Bias
1/3 bias is usually recommended for an LCD with three common terminals (1/3 duty). The waveform is shown in Figure
25-5 on page 307. SEG0-COM0 is the voltage across a segment that is “ON” and SEG0-COM1 is the voltage across a
segment that is “OFF”.