Adaptable I/O pad circuit for multiple voltage units bus operation

摘要

A voltage adapter pad circuit is presented, the circuit is oriented to applications where multiple digital units working at different voltage levels communicate in a bus connection. The active receiver pad circuit adapts the voltage of its, input stage to the power supply voltage levels of the active emitter unit equalising the noise margin of-the communication bus. Additionally the logic levels of the bus input are adapted to the inner voltage of the receiving system.