Re: Help, Fried 1-wire output

Will,


> What is the best way to trace this back to see what I fried?  Hopefully
> it is just U9 protection diode or U8 the 1-wire driver.

Most likely an internal resistor inside U9 is blown, which you can check
with a simple Ohm meter (a couple of days ago I also happened to
connect 5 V to the 1-wire bus).
According to the data sheet of the DS9503 approx. 5 Ohms should be
measured from pin 1 to 6 and from pin 2 to 5, respectively)
(data sheet: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2991)

Because I did not have a DS9503 for replacement I just soldered a
piece of wire as a short circuit for 1-6 and 2-5. It works fine for 
table top development without EMI (which sometimes could also read as
engineer's misfortune's interference)

If ListOW still does not find 1-wire devices, you should also replace
the 1-wire driver. There should be roughly 5 V at the output "whiggling" 
when talking to devices at the bus. An oscilloscope might be useful.

If in doubt, just replace the DS2480.

> 
> Is there a schematic for teh 400 socket board? I see the one listed for
> the 390 on the ibutton page, but couldn't find one for the 400.
> 

The schematic is hidden here:

pdfserv.maxim-ic.com/en/ds/DSTINIS-005-DSTINIS400.pdf

Good luck!

Regards

Klaus

_______________________________________________
TINI mailing list
TINI-6tN4nzCoH/[email protected]
To UNSUBSCRIBE, edit your profile, or see list archives:
http://lists.dalsemi.com/mailman/listinfo/tini