HD66781 Datasheet, PDF (183/196 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
Equalization function
The HD66781 incorporates source-Vcom equalization function, which short-circuits source outputs S1-
S720 and Vcom at alternating points to equalize the electric potential of source capacities and Vcom
capacities during “High” period of EQ signal.
By driving source and Vcom from the equalized electric potential, the electric charges accumulated in the
source and Vcom capacities are reallocated, and power consumption is reduced.
Normal Display
Equalization
+
+
+
S1
S720
EQ
EQ
EQ
EQ
VCOM
HD66781
+
+
+
S1
S720
EQ
EQ
EQ
EQ
VCOM
HD66781
EQ
HD66783/HD667P21
VCOM
EQ
HD66781/HD667P21
VCOM
Note 1) Equalization function is only available when Vcom Low level ≥ 0V
Note 2) Power-saving effects depend on display data.
Rev.0.5, July.31.2003, page 183 of 196