Voltage threshold detection circuit with very low power consumption

摘要

A supply-voltage-monitoring circuit, for low-power integrated circuits, in which charge-sharing through a switched-capacitor chain is used to couple the supply voltage to a dynamic sensing node. The dynamic sensing node drives a half-latch, which is stable in a no-alarm condition. In this circuit, the state of the output gets switched over in the first phase if the voltage at the terminals of the capacitor at the start of this stage (this voltage being equal to a fraction of the input voltage) crosses a determined threshold. This threshold is determined as a function of technical parameters for the construction of the circuit. These technical parameters are chiefly the threshold voltage of the transistor and the characteristics of the transistors that form the locking circuit.