IC Automates Removal Of TFT-LCD Panel Flicker

The STVM100 calibrator chip allows simpler and less expensive adjustments to thin-film transistor (TFT) LCD panels during manufacture in order to reduce the screens’ flicker. TFT-LCD panels have an inherent flicker that is eliminated in production by accurate adjustment of Vcom—the common voltage around the midpoint of the AVDD—using a potentiometer. By designing the STVM100 into the television set, this manufacturing adjustment can be made through the I2C interface instead, either through an operator control or as part of an automated process. Once the desired Vcom setting is found, its value can be stored in the chip’s internal EEPROM. This ensures that the TV can recall the calibration value automatically whenever the set is turned on. The EEPROM can be programmed repeatedly, so LCD manufacturers can calibrate the display panel as many times as needed. The chip provides 128 steps of Vcom adjustment, with three external resistors determining the highest and lowest values. The device comes in an 8-pin, 3 mm x 3 mm TDFN8 or a 3 mm x 3 mm TSSOP8 package. It is available now in volume, priced at $1.09 in quantities of 1,000. STMICROELECTRONICS, Lexington, MA. (888) 787-3550.