Sung-Pil Choi

Dynamic Slew-Rate Control for High Uniformity and Low Power in LCD Driver ICs

A slew-rate control method of LCD driver ICs is introduced to increase uniformity between adjacent driver ICs and reduce power consumption. The slew rate of every voltage follower is calibrated by a feedback algorithm during the non-displaying period. Under normal operation mode, the slew rate is dynamically controlled for improving power efficiency. Experimental results show that the power consumption is reduced by 16% with a white pattern and by 10% with a black pattern, and display defects are successfully eliminated.

EMI analysis of TFT-LCD driver IC

In this paper, design for EMC of LCD driver IC is proposed. By the analysis with package parasitic parameters and EMC test pattern, local power/ground noise in LCD driver IC simulated. As a result of analysis, design for lower peak of EMI spectrum and design for lower mean level of that is proposed at the same time. In addition, decoupling cap with CMOS process can decrease EMI spectrum without any further mask. The analysis of the proposed design shows that LCD driver IC can be alternatives for TFT-LCD EMC solution. It is because LCD driver IC is nearly irrelevant to LCD module whereas source PCB should be redesigned separately according to the size and resolution of LCD panel. The experimental result shows that the proposed design methodology for LCD driver IC can successfully decrease EMI spectrum of LCD module

A Low-Power Two-Line Inversion Method for Driving LCD Panels

A new two-line based inversion driving method is introduced for low power display-driver ICs. By inserting a timing offset between the chopper stabilization and the alternation of LCD polarity, we can reduce power consumption without noticeable degradation in the display quality. By applying the proposed scheme to 12″ LCD applications, we achieved 7.5% and 27% power saving in the display-driver IC with white and black patterns, respectively.