Speed-power-accuracy tradeoff in high-speed CMOS ADCs

Design of a 500-MS/s stochastic signal detection circuit using a non-linearity reduction technique in a 65-nm CMOS process

“…The supply voltages of RF and analog circuits embedded with digital circuits will decrease to 0.5 V in the near future [2]. Although some calibration techniques have conventionally been used to overcome increasing device mismatch, the architectures of analog signal detection based on conventional A/D converters (ADCs) are approaching their limit in maintaining resolution under such a low voltage supply [3].…”

A 6b 1.2 GS/s 47.8 mW 0.17 mm265 nm CMOS ADC for High-Rate WPAN Systems

“…(1, 2), respectively, while the required input signal range is derived as Eqs. (3,4) to operate all the transistors in the saturation region.…”

“…Especially, a reduced input signal range and high comparator offsets at a low supply voltage affect the overall performance of high-speed ADCs [3][4][5]. In case of flash-type ADCs commonly used for high speed conversion with a sampling frequency exceeding several hundreds of MHz, comparators determines most of the overall ADC power dissipation since the number of comparators is exponentially increased with a resolution.…”

“…The design targets of comparators are based on resolution, operating speed, input signal range, and offsets caused by device mismatch. The comparator offsets are proportional to the square of A Vt and A β , the device mismatch parameters of threshold voltage and mobility, and inversely proportional to the size of MOS transistor [3]. Although the device mismatch parameters have been improved considerably in the latest process technologies, the offsets by device mismatch have been rather increased due to the reduced size of MOS transistors [4].…”

“…As a result, the design targets of comparator tend to be more and more rigorous in a scaled-down process. Therefore, high-speed flash ADCs based on a lot of comparators have little benefits for power consumption in advanced CMOS technologies [3].…”