A 0.15-to-0.5 V Body-Driven Dynamic Comparator with Rail-to-Rail ICMR

Abstract

In this paper, a novel dynamic body-driven ultra-low voltage (ULV) comparator is presented. The proposed topology takes advantage of the back-gate configuration by driving the input transistors’ gates with a clocked positive feedback loop made of two AND gates. This allows for the removal of the clocked tail generator, which decreases the number of stacked transistors and improves performance at low VDD. Furthermore, the clocked feedback loop causes the comparator to behave as a full CMOS latch during the regeneration phase, which means no static power consumption occurs after the outputs have settled. Thanks to body driving, the proposed comparator also achieves rail-to-rail input common mode range (ICMR), which is a critical feature for circuits that operate at low and ultra-low voltage headrooms. The comparator was designed and optimized in a 130-nm technology from STMicroelectronics at VDD=0.3 V and is able to operate at up to 2 MHz with an input differential voltage of 1 mV. The simulations show that the comparator remains fully operational even when the supply voltage is scaled down to 0.15 V, in which case the circuit exhibits a maximum operating frequency of 80 kHz at Vid=1 mV.

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

“…The proposed comparator exhibits the best EDP among the standard-cellbased comparators in the literature (referring to both the 180nm and 130 nm implementations). The 130nm implementation of the proposed topology results in the best EDP also with respect to ULV full custom comparators, reaching a EDP of only 0.188[aJ /kHz] which is about 10 times lower than [46] which resulted in the lowest EDP in the recent literature. The area footprint of the proposed topology results much lower than the area of all other ULV comparators and it results about 5 times more compact than previously presented rail-torail ICMR standard-cell-based comparators considering the same technology node.…”