A method and an apparatus to detect low voltage have been disclosed. One embodiment of the apparatus includes a main circuit powered at a supply voltage, wherein the supply voltage changes over time and a test circuit coupled to the main circuit, the test circuit being representative of a voltage sensitivity of the main circuit to dynamically determine if the supply voltage is above a minimum voltage at which the main circuit operates correctly, wherein the minimum voltage changes over at least one of a temperature and a time and between different instances of the main circuit.