Location of 1/f noise sources in BJT's—II. Experiment

The exact location and magnitude of 1/f noise sources in silicon transistors was determined by a simple technique described in a previous publication [1]. This method, implementing the natural feedback action of actively biased devices, can generally be utilized to locate low-frequency noise generators in bipolar transistors. This paper presents measurements done on two silicon p+-n-p transistors. In the first device, the dominant noise source is due to generation-recombination, whereas the other less noisy device exhibits mainly diffusion noise.