A cost-effective offset cancellation structure for LCD source driver

This paper presents a cost-effective offset cancellation structure for liquid crystal display (LCD) source driver. The proposed structure eliminates the offset voltage by three switches and a capacitor. It samples the offset and reference voltages, and cancels it out from the data voltage. The output buffer is also modified, so the proposed circuit has rail-to-rail input and output range using only 19 transistors. The whole circuits are designed using standard library by 0.18-μm process. It exhibits average offset voltage of 1.85 mV and maximum difference of 39.6 μV by Monte Carlo simulation.