HD66781 Datasheet, PDF (173/196 Pages) Renesas Technology Corp – 720-channel Source Driver for a-Si TFT/Low Temperature Poly-Si TFT Panels with 262,144-color display RAM

HD66781
Preliminary
Oscillation Circuit
The HD66781 generates oscillation by an 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 operational power supply voltage. For example, the oscillation
frequency becomes low when increasing the value of Rf resistor, or lowering the power supply voltage.
See the “Notes to Electric Characteristics” section for the relationship between the Rf resistor value and the
oscillation frequency.
OSC1
Rf
OSC2
HD66781
External Resistor Oscillation Mode
Note 1) Place the Rf resistor as close to the OSC1, OSC2 pins as possible.
Note 2) Make sure not to arrange other wiring close to or beneath OSC1-OSC2 wiring to avoid effects from
coupling
Rev.0.5, July.31.2003, page 173 of 196