A 749nW 1MSps 8-bit SAR ADC at 0.5V employing boosted switches

Portability is an increasingly demanded feature in modern electronic system and circuit design, pushing ever tighter on power budget. Besides the well-known limitations on the power constraints, alternative power sources such as solar, vibrational and RF suggest the employment of also lower operating voltages, to match the sub-Volt levels generated by these sources. In this paper, we propose an 8-bit 1MSps SAR ADC in 90nm working with a 0.5V power supply, whose operation relies on an improved boosted switch. The ADC simulation results, including transient noise, exhibit a 7.67 effective number of bits (ENOB) for a full-scale input sinusoid near Nyquist frequency, while consuming 749nW. This leads to a figure-of-merit of 3.68fJ/conv.step.