An autocharge-compensated S/H circuit for TFT-LCD panel

Liquid-crystal displays (LCDs) have been widely used in TV and computer terminals. This article 1 shows a configuration of an LCD module composed of an LCD panel, signal segmentation ICs (SSICs) and a scanning-line controller. One horizontal video signal line, segmented and held in massive parallel S/H circuits in the SSICs, is transferred to a line of pixels through TFTs. The requirements for such a S/H are as follows: 1) sample time, determined by (horizontal scanning time)/(number of horizontal pixels), 2) 5 V full-scale operation range to control LC transparency, 3) over 30 MHz signal bandwidth, 4) low output offset standard deviation both within a chip and between chips, and 5) simple configuration.<>