An input and output buffer circuit which is contained in a first circuit operated on a first power source of a first voltage level Vcc1 and is permitted to connect to a second circuit operated on a second power source of a second voltage level Vcc2 higher than the first voltage level Vcc1 including:...http://www.google.fr/patents/US5880602?utm_source=gb-gplus-shareBrevet US5880602 - Input and output buffer circuit
