2005-04-18 09:08 PM
recommended state of un connected IOs
2005-04-17 12:40 AM
Hi !!
what is the recommended state of un connected ios ??? input/ output, shall i connected it through a resistor to the gnd ? leave connection open ???2005-04-17 05:01 PM
This is explained in datasheets in electrical section. Leaving the IOs as un-connected is not recommended. Pull-dn to gnd or pull-up to Vdd is the recommended state.
2005-04-18 12:25 AM
Why can't put the un-connected I/O pins in push-pull output?
It's the un-connected floating inputs that are normally the problem.2005-04-18 12:28 AM
This article has a good explanation:
http://massmind.org/techref/logic/xtrapins.htm2005-04-18 09:08 PM
Hi MD,
you are right No problem to keep the IO in o/p PP or OD low but The problem appears if the application is used in high noise environment.If the PC is lost because of some problem or ESD, the IO may become i/p floating and cause the consumption. Even o/p if shorted accidently to any signal can cause pb. So, if all possibilities are evaluated, there is always an agreement on external pU/pD.