HD66773R Datasheet, PDF (109/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
Internal Configuration of Power Generation Circuit
The internal configuration of power generation circuit of HD66773R is as follows. The step-up circuit is
comprised of the step-up circuit 1 which boost 2 to 3 times the voltage supplied with Vci1, the step-up
circuit 2 which further boost 2 to 4 times the voltage boosted by the step-up circuit 1, the step-up circuit 3
which invert the VGH-level voltage with the GND level as the axis and output the VGL-level voltage, and
the step-up circuit 4 which invert the Vci-level voltage with the GND level as the axis and output the VCL-
level voltage. The step-up circuit generates the voltage to drive a TFT LCD. Reference voltagea VDH,
Vcom and Vgoff for the grayscale voltage are generated either by being adjusted in the internal voltage
adjustment circuit or from the voltage at REGP, which is amplified in the amplifiers 1, 2. The Vcom,
Vgoff voltages can alternate at an arbitrary voltage level. Vcom must be connected to the panel.
Rev.1.10, Jun.21.2003, page 109 of 133