US Patent 7449916 Voltage level shift circuit

A voltage level shift circuit is provided. The circuit includes an input buffer unit, a level shift unit and a voltage stabilizing capacitor. The input buffer is coupled between a first voltage source and a first ground terminal. The level shift unit is coupled between a second voltage source and a second ground terminal. An input terminal of the level shift unit is coupled to an output terminal of the input buffer unit. The voltage stabilizing capacitor is coupled between the first voltage source and the second ground terminal. When a state transition occurs in the level shift unit, the voltage stabilizing capacitor maintains a voltage difference between the output terminal of the input buffer unit and the second ground terminal.