A Low Offset High Voltage Swing Rail-to-Rail Buffer Amplifier with for LCD Driver

This paper presents a design and implementation of an output buffer for LCD Driver with rail-to-rail voltage swing using TSMC 0.35 mum 2P4M process at 5 V supply. We designed a class-B output buffer with offset compensation ability to reduce the nonlinearity of output voltage. It performs a rail-to-rail swing range and high slew rate of 14 V / mus and 11.5 V / mus for rising and falling edges under a 400 pF capacitance load. For high driving capability , two push-pull output stages are used . two frequency compensation stages are also introduced for stability , One is the miller compensation with 0.04 pF capacitance , and the other is zero compensation with 0.1 kOmega added between two push-pull output stages for stable driving under different capacitance loads. The result exhibits the settling times of 0.7 mus for rising and 0.85 mus for falling edges with voltage swing 5 V under a 400 pF capacitance load. Even under a 1000 pF capacitance load , it still has the settling time of 1.52 mus and 1.80 mus for rising and falling edges , respectively. The effective area of this buffer is only 100 x 100 mum² with build-in offset voltage holding capacitor.