HD66789 Datasheet, PDF (132/156 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
n-raster-row Inversion AC Drive
The HD66789, in addition to LCD inversion AC drive by frame, supports n-raster-row inversion AC drive
where alternation occurs by n raster-rows, where n takes a number between 1 to 64. The n-raster-row
inversion AC drive enables to overcome the problems related to display quality.
In determining n (the value set in the NW bit +1), the number of raster-rows by which alternation occurs,
check the display quality on the actual liquid crystal panel. Setting a small number of raster-rows will raise
the AC frequency of the liquid crystal and increase the charge/discharge current on the liquid crystal cells..
Back porch
1 frame
Front porch Back porch
1 frame
Front porch
Frame AC driving
240-raster-row driving
1234
241 242
256 1 2 3 4
241 242
256 ^{1 2}
n-raster row driving
240-raster-row driving
3-raster-row reversed
EOR = 1
Note: Make sure that EOR is set to "1" whenever the n-raster-row reverse AC driving to avoid DC bias.
n-raster-rows inversion AC drive
Rev.0.12, May 09 2003, page 132 of 156