Metal-oxide-semiconductor capacitor based charge sharing successive approximation register data converter

Abstract

An image sensor may include an analog-to-digital converter. The converter may have a input capacitor, one or more metal-oxide-semiconductor capacitors, a digital-to-analog converter, and a comparator. An input signal may be sampled onto the input capacitor while the metal-oxide-semiconductor capacitors are activated. A few conversion steps may be performed while the metal-oxide-semiconductor capacitors are activated. After the few conversion steps, the metal-oxide-semiconductor capacitors are deactivated to realize a voltage gain, which makes the converter less sensitive to comparator noise.