HD66781 Datasheet, PDF (73/196 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
Common registers for HD66783 and HD667P21
BT[2:0]: Change the output scale of step-up circuits. Adjust the step-up scale according to the voltage in
use. To set power consumption lower, it is necessary to set the step-up scale smaller. For details, see the
datasheets of HD66783 and HD667P21.
VCOMG: Make settings for the output level of VcomL.
VCOMG = 0
VCOMG = 1
The low-side output of Vcom is fixed to GND and the instruction (VDV) setting
becomes invalid. Outputs from VcomL and VCL are halted.
For this reason, the VCOMG setting is related to the power-supply startup
sequence. Make a VCOMG setting by following the power-supply setting
sequence.
The low-side output of Vcom becomes VcomL. The output voltage of VcomL is
set by instruction (VDV) setting. VCOMG = 1 is valid when PON = 1.
VC[2:0]: Adjust the reference voltages of VREG1OUT, VREG2OUT, and Vci1 voltages according to Vci
as the reference voltage. For details, see the datasheets of HD66783 and HD667P21.
VRH[3:0]: Set the amplifying scale of VREG1OUT with the values set in VC bits (REGP) as an input.
For details, see the datasheets of HD66783 and HD667P21.
VCM[4:0]: Make a setting for VcomH (the “High” of Vcom). VcomH can be amplified to VREG1OUT x
0.41 ~ 1.00. When VCM = 5’h01, VcomH is not adjusted by the internal volume adjustment but by an
external resistor from VcomR. For details on whether to generate the VcomH level with internal electronic
volume or an external resistor, see the datasheets of HD66783 and HD667P21.
VDV[4:0]: Set the Vcom alternating amplitude. The setting is invalid without Vcom alternating drive. For
details, see the datasheets of HD66783 and HD667P21.
Registers of HD66783
AP[2:0]: Adjust the amount of constant current in the operational amplifier in the liquid crystal drive
power supply. When the amount of constant current is set large, the liquid crystal drive capacity is
enhanced and the display quality will improve, while the current consumption will increase. Select an
optimum amount of current taking both the display quality and the current consumption into account.
When no display operation is required, set AP[2:0] = “3’h0” to halt the operation of operational amplifiers
and step-up circuits to reduce the current consumption. To set AP[2:0] otherwise, it starts step-up circuits
to output VGH. For details, see the datasheets of HD66783.
DC0[2:0]: Select the operation frequency of step-up circuit 1. If the step-up operation frequency is set high,
display quality will be enhanced due to increased drive capacity of step-up circuit, while power
consumption will be increased. Make an adjustment taking both display quality and power consumption
into consideration. For details, see the datasheets of HD66783.
GON: When GON=0, the output level of G1~G320 pins of HD66783 becomes VGH and the Vcom level
becomes GND.
Rev.0.5, July.31.2003, page 73 of 196