Abstract
The operational amplifier is one of the most significant performance bottlenecks in traditional Analog-to- Digital Converters. CMOS technology down-scaling results in lower voltage swings and transistor intrinsic gain. This trend increases the challenges in designing analog and mixed-signal circuits. This paper reviews a few promising patents on new development of analog-to-digital converters. The challenges in traditional operational amplifier based ADCs are analyzed.
Keywords: Operational amplifier, pipelined ADC, SAR ADC, Analog-to-Digital Converters, Gain boost, Replicated operational amplifier, open-loop AC response