Rail to Rail ICMR and High Performance ULV Standard-Cell-Based Comparator for Biomedical and IoT Applications

Abstract

In this paper a novel ultra-low voltage (ULV) standard-cell-based comparator which provides rail-to-rail input common-mode range (ICMR) is presented. The topology, unlike the others in the literature, uses only 2-inputs NAND gates and is able to operate with supply voltages as low as 0.15V. A detailed theoretical analysis based on transistor level modeling is provided to explain the operating principle and highlight the performance advantages of the proposed comparator. The circuit has been tested through several simulations, including corner analysis and Monte Carlo runs, by using three different technologies: 180 nm, 130 nm and 28 nm for both a supply voltage of 0.3 V and 0.15 V. The results found not only confirm the robustness of the proposed comparator, but also demonstrate very advantageous performances. Indeed, for the same technology node it exhibits the highest speed and the lowest EDP (about ten times lower than the one of the others standard-cell-based comparators in the literature). It exhibits also the lowest power consumption and silicon area.

Body Biasing Techniques for Dynamic Comparators: A Systematic Survey

“…It is important to acknowledge that this analysis overlooks the fact that the second integrator is a time-varying system due to the linear increase of g m is scaled by a factor different from 1/2 yet still less than one. While Equations (10) and (11) are different, they indicate that both topologies exhibit similar responses to FBB in terms of noise. In both scenarios, < V 2 noise > decreases as a function of V th 3,4 and V th 5,6 , consequently worsening the inputreferred noise due to the reduction in threshold voltages caused by FBB.…”

“…The analysis of noise leads to different expressions for the Strong Arm latch and the Elzakker comparator. According to [27], the mean square input-referred noise of the Strong Arm latch can be expressed as (10) where Υ is the noise factor of the FET and V th = V th 3,4 ≈ V th 5,6 . The authors of [27] do not provide an expression for the input-referred noise of the Elzakker comparator; nonetheless, ref.…”

“…Dynamic latched comparators are also attractive because their performance improves as technological scaling advances, unlike open-loop comparators based on cascading high-gain elements. Thanks to their properties, dynamic comparators are employed in a wide variety of scenarios, ranging from low-and ultra-low voltage systems [6][7][8][9][10] to high-speed applications [11][12][13][14].…”