HD66766R Datasheet, PDF (67/97 Pages) Hitachi Semiconductor – 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors

HD66766R
Rev. 1.0-1 / September 2002
Oscillation Circuit
The HD66766R 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 decreased, the oscillation frequency decreases. For the relationship between Rf
resistor value and oscillation frequency, see the Electric Characteristics Notes section.
1) External clock mode
Clock
(264kHz)
Damping resistance
(2kΩ)
OSC1
OSC2
HD66766R
2) External resistance
oscillation mode
Rf
OSC1
OSC2
HD66766R
Note: The resistance must be located
near the OSC1/OSC2 pins.
Figure 51 Oscillation Circuits
The relationship between the SEG and COM output levels is as shown in the following figure. While the
display is off, SEG and COM outputs go to GND level.
M
VCH
COM waveform
VS
VM
VSL (GND)
No lit
Lit Lit
SEG waveform
Lit
No lit No lit
VCL
Figure 52 Relationship with SEG/COM Output Level
67