Effects of open-loop nonlinearity on linearity of feedback amplifiers

A quantitative analysis of the effects of nonlinearity in an open loop amplifier on the linearity of negative feedback amplifiers is presented. Results show that the ratio of the open-loop nonlinearity (OLN) to the closed-loop nonlinearity (CLN) in the presence of varying amounts of secondand third-order nonlinearities in the open loop amplifier is quantified. Results show that for the same amount of nonlinearities in the open loop amplifier, the second-order nonlinearity is suppressed more through feedback than the third-order nonlinearity. The effect of high open loop gain on reducing the nonlinearities through negative feedback is limited.