Bistable noise in operational amplifiers

Bistable noise in operational amplifiers has been investigated. Equivalent circuits are used. It is shown that by changing the source resistance of an operational amplifier the locations of bistable noise sources can be determinated. Both burst noise and microplasma noise observed from an operational amplifier. The input transistors of an operational amplifier are the most important bistable noise sources. Burst noise due to elements other than the input transistors is shown to be important. Surface effects on burst noise have been discussed. Because of the surface effect, n-p-n transistors are expected to show more burst noise than p-n-p transistors. Microplasma noise in an operational amplifier is attributed to a local surface breakdown.