Voltage adjusting circuit, contactless card and contactless card system having the same, and methods of operating the voltage adjusting circuit and the contactless card

摘要

A voltage adjusting circuit is provided includes an inducing circuit configured to induce a voltage from electromagnetic waves, a first rectifying circuit configured to rectify an output voltage of the inducing circuit, a control circuit configured to control an output voltage of the first rectifying circuit in response to the output voltage of the first rectifying circuit, and a second rectifying circuit configured to simultaneously rectify and regulate the output voltage of the inducing circuit in response to the output voltage of the first rectifying circuit.