Patent ID: 6954100
Filing Date: 2005-10-11
Classification: H03K

Abstract:
1. An integrated circuit with a bi-directional level shifter, the bi-directional level shifter comprising: a first signal terminal operable as an input and an output, wherein when being operable as an input, the first signal terminal receives a first signal compatible with a first voltage domain of the integrated circuit and wherein when being operable as an output, the first signal terminal provides a shifted signal compatible with the first voltage domain of the integrated circuit; a second signal terminal operable as an output and an input, wherein when being operable as an output, the second signal terminal provides a shifted sign compatible with a second voltage domain of the integrated circuit and wherein when being operable as an input, the second signal terminal receives a second signal compatible with the second voltage domain of the integrated circuit; and level shift circuitry coupled between the first signal terminal and the second signal terminal, the level shift circuitry translating the first signal compatible with the first voltage domain to the shifted signal compatible with the second voltage domain when the first signal terminal is operable as an input, the level shift circuitry translating the second signal compatible with the second voltage domain to the shifted signal compatible with the first voltage domain when the second signal terminal is operable as an input; wherein the level shift circuitry further includes at least one current cut-off transistor, wherein responsive to being non conductive, the at least one current cut-off transistor operates to cut off current flowing in a current path between a first voltage domain voltage supply and second voltage domain voltage supply; wherein the at least one current cut-off transistor includes a first cut-off transistor disposed within the first voltage domain and a second transistor disposed within the second voltage domain.