What to do with all those left over pins

JonJon

Guys,

What is one to do with all the left over port pins that are not used in an application of an sx chip.· I've noticed that I get very noisy transistions on open pins that are configured at High Z for imput but not connected.· Is there a standard parctice for these orphaned guys???· I do notice that when I configure these for output with '0' the noise seem to stop and things settle down.

Regards,

JJ

·

James Newton

http://www.sxlist.com/techref/logic/xtrapins.htm

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
---
James Newton, Host of SXList.com
james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!

JonJon

Now that is what I call an answer. Complete quick and concise!

Thanks James!

JJ

Jim G.

Thanks for posting this excellent question; I will be changing my practice a little... ;-)

When considering whether to tie a spare pin high or low, I often tie it high through a resistor, since many chip's i/o ports·can sink more current than they can source.· This way, if I need to use the pin for something later,·the "active" state is the low, high drive state.

My $0.02.

Jim