The 33884 Switch Monitor Interface is a monolithic silicon integrated circuit (IC) to perform switch monitoring functions. The device provides efficient interface between electrical switches and low voltage microprocessors. The 33884 supplies switch contact pull-up and pull down current while monitoring the input voltage level. All inputs are protected for transients when implemented with an appropriate static discharge capacitor used on the inputs. There are four modes of operation: Sleep, Normal, Polling, and Polling + INT Timer.