HD66789 Datasheet, PDF (20/156 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
DISPTMG, and SFTCLK) are generated internally, and a part of the signals is output through a level
transforming circuit.
8. Oscillation Circuit (OSC)
The HD66789 can provide R-C oscillation simply by placing an external oscillation-resistor between OSC1
and OSC2 pins. An appropriate oscillation frequency for operating voltage, display size, and frame
frequency can be obtained by adjusting the external-resistor value. Clock pulses can be supplied externally.
Since R-C oscillation is halted during the standby mode, current consumption will be reduced. For details,
see the “Oscillation Circuit” section.
9. LCD Driver Circuit
The LCD driver circuit of HD66789 consists of a 528-output source driver (S1 ~ S528) and a 240-output
gate driver (G1 ~ G240). Display pattern data are latched when 528-bit data arrive. The latched data
controls source driver and generates drive waveforms. The gate driver, which operates display scan, selects
either VGH or VGL level to output. The shift direction of outputting 528 bits from source driver is
changeable with the SS bit. The shift direction of gate driver scan is changeable with the GS bit. The scan
mode of gate driver is changeable with SM bit. Select an appropriate shift direction and mode for an
assembly.
10. Liquid crystal drive power supply circuit
The LCD drive power supply circuit of HD66789 generates voltage, V0, V31P, V31N, VGH, and Vcom
required for driving LCD.
Rev.0.12, May 09 2003, page 20 of 156