A rail-to-rail CMOS operational amplifier with programmable compensation schemes

A rail-to-rail CMOS operational amplifier (Op Amp) with programmable compensation schemes is designed using standard 0.35 /spl mu/m CMOS process. An efficient MOS capacitor is used to compensate the stability of the Op Amp. A compensation current switch is used to adjust the slew rate. Using the schemes, the Op Amp can obtain improved the stability, bandwidth, slew rate and settling time according to the output load.