Patent ID: 7663430
Filing Date: 2010-02-16
Classification: G05F

Abstract:
1. A voltage supply circuit having an input terminal for receiving an input voltage, and an output terminal for outputting an output voltage, comprising: a first voltage drop component, coupled between the input terminal and the output terminal, for generating a first voltage drop from the input terminal to the output terminal; a second voltage drop component, coupled between the input terminal and the output terminal, for generating a second voltage drop from the input terminal to the output terminal; and a control module, coupled to the first voltage drop component, for controlling a conducting state or a non-conducting state of the first voltage drop component; wherein, when the first voltage drop component is controlled by the control module in the conducting state, the output voltage is substantially equal to the input voltage minus the first voltage drop; when the first voltage drop component is controlled by the control module in the non-conducting state, the output voltage is substantially equal to the input voltage minus the second voltage drop; and the first voltage drop is different from the second voltage drop; wherein the control module comprises a first capacitor having a first capacitance, and the control module changes the state of the first voltage drop component from the conducting state to the non-conducting state according to a voltage across the first capacitor.