ASTLC5505A - ALL-IN-ONE CHIP FOR SMALL-SIZE TFT-LCDs
DESCRIPTION
The ASTLC5505A is a single chip solution dedicated to small size color TFT-LCDs. It combines on the same substrate a source driver, a gate driver, a timing controller and a power supply circuit. The system can be configured either through a 3-wire serial interface or through several individual control pins.
The 480-output channels source driver have 6-bit resolution or 8-bit if the dithering technique function is selected. The gamma correction is implemented with a resistor ladder using 4 sections of reference voltage to improve the output voltage deviation while the total value of the ladder is optimized for low power consumption.
A DC-to-DC controller and several charge pumps form the on chip power management circuit. The DC-DC generates the panel backlight supply voltage while charge pumps are used to generate the gate driver supply and common drivers supply voltages. The DC voltage level of the output common signal can be adjusted through a variable external resistor and the peak-to-peak amplitude can be selected through the setting of 3 external pins.
The timing controller supports 8 different timings suitable for small size color TFT panels with PAL and NTSC.
FEATURES
- System-on-chip (SOC) for small size color TFT-LCDs, including:
- Source driver with 480-channels, 6-bit (64 grayscale) resolution, line inversion, gamma correction with 5 external references
- Gate driver: 242-outputs
- Timing controller supporting 8 different timings
- CCIR 656 interface compatible with ITU-R BT.656 recommendation
- DC-DC controller of back-light power supply
- Charge pump for gate driver output: +12.5V/-12.5V
- 3-bit programmable DC voltage level for VCOM
- 3-wire serial interface for system configuration
- Stand-by mode - LCD driver supply voltage: 3.0V ~ 3.6V
- Charge Pump supply voltage: TBD ~ 3.6V
- Digital supply voltage: 2.7 ~ 3.6V
- Operating frequency: 27MHz
- COG package
Block diagram
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