HD66789 Datasheet, PDF (131/156 Pages) Renesas Technology Corp – 528-channel, One-chip Driver for Amorphous TFT Panels with 262,144-color display RAM, Power Supply Circuit, and Gate Circuit

HD66789
Preliminary
Oscillation Circuit
The HD66789 generates oscillation by internal R-C oscillator with an external oscillation resistor placed
between the OSC1 and OSC2 pins. The oscillation frequency varies depending on the value of external
resistor, the distance of wiring, and the power supply voltage for the oscillation. For example, the
oscillation frequency becomes low when increasing the value of Rf resistor, or lowering the power supply
voltage. See the “Electric Characteristics Notes” section for the relationship between the Rf resistor value
and the oscillation frequency.
OSC1
Rf
OSC2
HD66789
OSC1
Rf
OSC2
HD66789
External Resistor Oscillation Mode
Note 1) Place the Rf resistor as close as to the OSC1, OSC2 pins.
Note 2) Make sure not to arrange other wiring beneath or close to OSC1-OSC2 wiring to avoid effects from
coupling.
Rev.0.12, May 09 2003, page 131 of 156