Out of band interference measurement of negative feedback amplifiers

A simplified measurement procedure is proposed in the determination of out of band signal sensitivity of negative feedback amplifiers. Generally, radiation measurements are best able to emulate practical situations, but are cumbersome and difficult to set up. In the case of negative feedback amplifiers, however, direct injection at the input appears to adequately characterise the device under test. This is verified by carrying out irradiation and injection measurements of a family of operational amplifiers and comparing the relative sensitivities to out of band interference thus obtained