Burst noise is a type ofelectronic noise that occurs in semiconductors and ultra-thin gate oxide films.[1] It is also calledrandom telegraph noise (RTN),popcorn noise,impulse noise,bi-stable noise, orrandom telegraph signal (RTS) noise.
It consists of sudden step-like transitions between two or more discrete voltage or current levels, as high as several hundredmicrovolts, at random and unpredictable times. Each shift in offset voltage or current often lasts from several milliseconds to seconds, and sounds likepopcorn popping if hooked up to an audio speaker.[2]
Burst noise was first observed in earlypoint contact diodes, then re-discovered during the commercialization of one of the firstsemiconductorop-amps; the 709.[3] No single source of burst noise is theorized to explain all occurrences, however the most commonly invoked cause is the random trapping and release ofcharge carriers at thin film interfaces or at defect sites in bulksemiconductor crystal. In cases where these charges have a significant impact on transistor performance (such as under a MOS gate or in a bipolar base region), the output signal can be substantial. These defects can be caused by manufacturing processes, such as heavyion implantation, or by unintentional side-effects such as surface contamination.[4][5]
Individual op-amps can be screened for burst noise with peak detector circuits, to minimize the amount of noise in a specific application.[6]
Burst noise is modeled mathematically by means of thetelegraph process, a Markovian continuous-timestochastic process that jumps discontinuously between two distinct values.
Today, although burst noise can still occasionally occur during manufacturing, the phenomenon is sufficiently well understood that affected devices are detected and scrapped during test.