CMOS operational amplifier with nearly constant settling time

An operational amplifier with a settling time nearly independent of the signal amplitude and the capacitive load has been realised in CMOS technology. It uses an additional circuit to inject an extra bias current into the bias circuit of the operational amplifier. This measure substantially increases the slew rate of an operational amplifier for a given quiescent current. It is useful for programmable high-frequency switched-capacitor circuits, because it always yields an optimum performance without any tailoring.