Characterization of RTN noise in the analog front-end of digital pixel imagers

The interest for more digital functionality in the readout circuits for imagers is growing rapidly. Similarly, there are advantages to having the pixel pitch smaller from visible to long wave IR. The front end is the dominant source of electronic noise for an in-pixel digital design. Limiting the real estate considerably would force the design to smaller feature size, which may worsen the random telegraph signal or noise (RTS/RTN) that will likely be the dominate source for noise for these imagers. This paper summarizes initial results for RTN sensitivities at room temperature to various device types, geometries, and flux rates, evaluated on a digital pixel on 65- and 55-nm CMOS processes.