The Institution of Engineering and Technology 2017. A reference switching pre-emphasis (RSP) technique is proposed for successive approximation register (SAR) ADC in order to improve the SAR DAC settling time, which limits the conversion speed of conventional SAR ADCs. While SAR ADCs that employ redundancy techniques relax DAC settling requirements by overlapping search spaces, this requires more conversion steps which offsets the benefit from the DAC settling relaxation, especially for low-medium resolution SAR ADCs. The proposed RSP technique improves DAC settling by breaking its dependence on ADC resolution and achieves up to 71% speedup of DAC settling relative to a conventional DAC switching scheme without introducing additional conversion steps or significant hardware overhead.
