A 270-MS/s 6-b SAR ADC with preamplifier sharing and self-locking comparators

[摘要] References(5)This paper presents a high speed SAR ADC with distributed comparators and shared preamplifiers. In contrast with the previous design, the sharing preamplifier technique avoids input range degradation and comparators�? offset calibration. Also, the paper proposes a self-locking dynamic comparator to maintain its high speed and high robustness. Moreover, it consumes less power than traditional single cross-coupling comparator. The ADC is fabricated in 0.13 µm CMOS technology to achieve a performance of 6-b resolution at 270-MSps rate. Its power consumption is 4.25 mW under a supply of 1.2 V. The measurement results shows the ADC achieves an ENOB of 5.65b with a low frequency input and 5.17b with a up-to-Nyquist frequency input. The FoM of the proposed ADC is 313-fJ/conversion step.

[学科分类] 电子、光学、磁材料

[关键词] successive approximation register;analog-to-digital convertors;preamplifier;comparators