HD66781 Datasheet, PDF (6/196 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
Description
The HD66781 is a 720-channel source driver with graphics acceleration function, incorporating RAM
compliant to 262,144 TFT colors and 240RGB x 320 dot graphics. In combination with the HD66783,
which incorporates a power-supply integrated circuit and a gate driver on a single chip, the HD66781 can
drive an a-Si TFT panel of 240 RGB x 320 dots at maximum. Also in combination with the HD667P21,
which is a power-supply IC chip, the HD66781 can drive a low-temperature poly-Si TFT panel of 240 RGB
x 320 dots at maximum with an incorporated gate driver.
The HD66781’s high-speed RAM-write function through a high-speed interface of 8/9/16/18-bit bus
enables efficient data transfer with high-speed burst RAM write function. The HD66781 is compliant to
DMA transfer single address mode to keep control on bus traffic occupation when a large volume of data is
transferred from external memory. The HD66781 can also handle moving picture display through an RGB
interface (VSYNC, HSYNC, DOTCLK, ENABLE, and PD 17 to 0).
The HD66781 incorporates RAM with the capacity of one QVGA-sized whole screen of 240 RGB x 320 x
18bits plus 96 raster-rows. In addition to OSD and α blending functions, which use this RAM area, the
HD66781 also handles resizing function, which is compliant to data transfer for a large screen display.
These functions make the HD66781 the best solution for the efficient and various ways of display.
The combined use of HD66781 with HD66783 or HD667P21 supports the function to reduce power
consumption by a liquid crystal display system. The HD66781’s RAM can display 240 RGB x 320-dot
color display (max.) with low voltage operation up to 1.7 V. The HD66781 incorporates a voltage follower
circuit to generate liquid crystal driving voltages and an interfacing circuit that enables through HD66781
to make instruction settings to HD66783 and HD667P21. In addition, the HD66781 supports power-saving
modes such as standby mode and 8-color display mode, which allow precise power management by
software. These features make this LSI the ideal solution for medium or small-sized portable battery-
driven products such as digital cellular phones or small PDA with color displays, where long battery life
and board size are a major concern.
Rev.0.5, July.31.2003, page 6 of 196