HD66730 Datasheet, PDF (109/131 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver Supporting Japanese Kanji, Korean Font Display

HD66730/HD66731
Oscillator
Figure 41 shows the optimal value of the oscillation frequency or the external clock frequency depends on
the duty drive ratio setting (DT1/0), number of display lines (NL1/0), and the number of display characters
(NC1/0) in the HD66730/1. The oscillation frequency or the external clock frequency must be adjusted
according to the frame frequency of the liquid crystal drive.
1) When an external clock is used
2) When an internal oscillator is used
Clock
OSC1
HD66730
HD66731
OSC1
Rf
OSC2
HD66730
HD66731
Note: The oscillator frequency can be adjusted by an oscillator resistor (Rf). Refer to Electrical
Characteristics for the relationship between the oscillator resistor (Rf) and the oscillator
frequency. If Rf is increased or power supply voltage is decreased, the oscillator frequency
decreases.
Figure 41 Oscillator Connections
108