HD66760 Datasheet, PDF (67/105 Pages) Hitachi Semiconductor – 104 X 80-dot Graphics LCD Controller/Driver for 256 Colors

HD66760
Oscillation Circuit
The HD66760 can oscillate between the OSC1 and OSC2 pins using an internal R-C oscillator with an
external oscillation resistor. Note that in R-C oscillation, the oscillation frequency is changed according to
the external resistance value, wiring length, or operating power-supply voltage. If Rf is increased or power
supply voltage is decrease, the oscillation frequency decreases. For the relationship between Rf resistor value
and oscillation frequency, see the Electric Characteristics Notes section.
OSC1
Rf
OSC2
Note: Put the Rf resistor as close
as possible to the OSC1 and
OSC2 pins.
HD66760
Figure 45 Oscillation Circuits
Table 35 Relationship between Liquid Crystal Drive Duty Ratio and Frame Frequency
LCD Duty
Recommended
NL4–0 Set Value Drive Bias Value Frame Frequency One-frame Clock
1/16
01H
1/5
70 Hz
2560
1/24
02H
1/6
70 Hz
2560
1/32
03H
1/6
70 Hz
2568
1/40
04H
1/7
70 Hz
2560
1/48
05H
1/8
71 Hz
2544
1/56
06H
1/8
70 Hz
2576
1/64
07H
1/9
70 Hz
2560
1/72
08H
1/9.5
71 Hz
2520
1/80
09H
1/10
70 Hz
2560
Note: The frame frequency above is for 180-kHz operation and proportions the oscillation frequency (fosc).