Input stage for mixed-voltage-tolerant buffer with reduced leakage

摘要

A mixed-voltage buffer circuit coupled between a first circuit operative at a first power supply voltage and a second circuit operative at a second power supply voltage. The buffer circuit is connectable to the second power supply voltage and a third power supply voltage and includes an input circuit coupled to the first circuit through a first node and to the second circuit through a second node. The input circuit includes a first part coupled to the first node and an inverter coupled to the second node. The first part provides a signal having a voltage level approximately equal to the third power supply voltage to the inverter in response to a first signal on the first node, and provides a signal having a voltage level approximately equal to the second power supply voltage to the inverter in response to a second signal on the first node.