VCom calibrator reduces manufacturing costs in TFT-LCDs

The ISL45041 incorporates an I2C interface and a 128-step adjustable sink current output current control. Its digital interface controls the sink-current output that attaches to an external voltage driver to establish the required Vcom voltage setting.

Adjusting the Vcom of TFT-LCD panels is a labour-intensive process that can be simplified by using the ISL45041 non-volatile Vcom calibrator. Not only does the device allow users to replace one of the last mechanical stages in TFT-LCD panel assembly - reducing labour time and costs - but it also significantly increases reliability.

The ISL45041 also includes an EEPROM (erasable programmable read only memory) bank, features industry-leading electrostatic discharge ratings, and operates using a lower supply current than competitive devices. The device lets customers easily set and drive the desired Vcom voltage on the TFT-LCD panel via the I2C interface and with a resolution of 7 bits. Once the ideal value is found, it can be programmed and stored in the on-board non-volatile EEPROM memory bank. Then, after it is set, the Vcom voltage can be driven throughout the common backplane via a high-performance rail-to-rail input and output, high-output-current Vcom driver.
Key features of the ISL45041 include an analogue voltage range of 4.5V to 18V, a digital voltage range from 2.25V to 3.6V, an output adjustment SET pin, and an output that is guaranteed to be monotonic over temperature. Target applications for the device include TFT-LCD screens for televisions, notebook computers, and monitors.