OP补偿

caroline11

Abstract – A MOS-cascode load element can be used in the high ohmic output path of an operational amplifier in folded cascode topology. It delivers a doublet that has very low impact on the frequency response and the stability of the operational amplifier. For switched capacitor applications not only stability but also settling time is a very important parameter for the whole circuit performance. It will be shown that a doublet produces a very slow settling component due to the fact that the pole and the zero do not cancel exactly. Depending on the absolute frequency of the doublet and the pole/zero spacing the time constant and the amplitude of this very slow settling component can be determined.