Patent ID: 6034550
Filing Date: 2000-03-07
Classification: H03K

Abstract:
A multiple-power IC device comprising:an input buffer circuit for receiving an input signal and a plurality of power voltages of different magnitudes, said input buffer circuit having an output associated with each of said plurality of power voltages for outputting said input signal in accordance with a predetermined threshold voltage;an internal circuit;a switching circuit interposed between said input buffer circuit and said internal circuit; anda power voltage determination circuit coupled to said switching circuit and receiving said plurality of power voltages said power voltage determination circuit controlling said switching circuit to selectively couple an output of said input buffer circuit to said internal circuit in accordance with the magnitude of the received power voltage, whereby the input signal is coupled to said internal circuit according to said predetermined threshold voltage regardless of the power voltage applied to the input buffer circuit;wherein said input buffer circuit comprises a plurality of input buffers, each of said input buffers having an output, an input for receiving said input signal, and an input for receiving said plurality of power voltages, the threshold voltage of each of said input buffers equaling said predetermined threshold voltage for an associated power voltage.