Cmos image sensing with sampled bandgap reference

Abstract

Techniques are described for sampled bandgap reference generation for CMOS image sensor (CIS) applications. For example, the CIS includes a pixel array, one or more pixel analog to digital converters (ADCs), and a sampled bandgap reference generator, all integrated in close proximity on a chip. The ADCs rely on stable reference levels from the bandgap reference generator for performing pixel conversions for the pixel array. Embodiments of the sampled bandgap reference generator can operate according to reference generation cycles. Each cycle can include a first portion, in which an active core dynamically stabilizes the bandgap reference level; and a second portion, in which the core is deactivated, and the bandgap reference level is output based on a sampled level obtained during the preceding first portion of the cycle. The cycle timing can be controlled to achieve sufficient dynamic stabilization of the reference levels, while mitigating photon emissions from the core.