An Accurate 0.55-V 2.6-μW Voltage-Level Detector

A CMOS voltage-level detector (VLD) circuit is proposed for Internet-of-Things systems which operates near the minimum energy point. It can accurately detect VCC levels of 550-640 mV, making it one of the lowest voltage VLDs reported to date. A novel pull-up circuit is utilized to accurately detect fast VCC ramps of 10's of microseconds, which are faster than the power-up of the VLD itself. This feature enables it to operate at a low power consumption of 2.6 uW. A low voltage, charge-pumped bandgap reference is utilized with a highly accurate comparator to achieve a 35-mV variation across temperature and a random variation sigma of 1.68 mV. This circuit is one of the lowest voltage, most highly accurate, and fastest ramp-detect VLDs that have been reported in the literature.