System and Method for Communicating with an Unpowered Device

An apparatus for performing operations using low power, including control circuitry; a radio frequency (RF) circuit for receiving RF signals at one or more frequencies; an internal power source; and switching circuitry coupled between the control circuitry and the internal power source, the switching circuitry having a control terminal coupled to an output of the RF circuit. The apparatus is configured in a normal mode of operation and an off mode of operation in which the apparatus is powered down, and wherein in the off mode of operation energy from the received RF signals control a state of the switching circuitry to selectively couple the internal power source with the control circuitry for performing one or more operations.