Switch Controlled Source Amplifier for Low Power Mobile TFT-LCD Driver IC

Switch controlled source amplifier (SCSA) is proposed for low power mobile TFT-LCD driver ICs (T-LDIs). In SCSA scheme, the operation of the source drivers in a T-LDI is determined by the source line load of TFT-LCD. That is, output stage current of source buffers is reduced when the source line load is separated for current saving operation such as charge sharing between VCOM and source lines. With SCSA scheme, all the static current of source buffers can be reduced as far as phase margin of the output buffers is permitted. A test chip was fabricated in a 5-V/0.8-mum triple-metal CMOS process with QVGA resolution, and the experimental results show that the power consumption of 11%~16% was saved with die size overhead less than 1%.