General purpose input/output's buffer with reverse current protection capability in above supply level condition

A general purpose input output (GPIO) interface is briefly overviewed in current paper, with the main focus on the output circuitry portion. As a result a GPIO output buffer for portable applications is proposed with up to 5mA load driving capability, an overlap protection and ability for reverse current protection in off state when output is pulled above supply rail. The buffer is able to work at frequencies up to 10MHz with a maximum supply current of 70μA.