A Low-Area Reference-Free Power Supply Sensor

Power supply unpredictable fluctuations jeopardize the functioning of several types of current electronic systems. This work presents a power supply sensor based on a voltage divider followed by buffer-comparator cells employing just MOSFET transistors and providing a digital output. The divider outputs are designed to change more slowly than the thresholds of the comparators, in this way the sensor is able to detect voltage droops. The sensor is implemented in a 65nm technology node occupying an area of 2700 μm² and displaying a power consumption of 50 uW. It is designed to work with no voltage reference and with no clock and aiming to obtain a fast response.