This application note describes how to design a high reliability rotary switch or encoder using a Dialog GreenPAK. This switch design is contactless, and therefore ignores contact oxidation and wear. It is ideal for use outdoors where there is long term moisture, dust, temperature extremes, etc.
Dialog GreenPAK SLG46537: The GreenPAK CMIC provides all the circuit functions for this design. It generates a signal (EVAL) for improved signal to noise, receives inputs from each sector pad of the rotary switch, and interprets each sector pad using the Asynchronous State Machine(ASM) to guarantee only one switch selection.