Interface slow 5V signals

Technical discussions around xCORE processors (e.g. xcore-200 & xcore.ai).
Post Reply
User avatar
skoe
Experienced Member
Posts: 94
Joined: Tue Apr 27, 2010 10:55 pm
Contact:

Interface slow 5V signals

Post by skoe »

Can I connect slow 5V signals using a series resistor of about 1 k to the XMOS' I/O ports? Will the clipping diodes be enough in this case to protect the inputs? It's just a test circuit, nevertheless I don't want to blow up my XMOS.

Regards,
Thomas


User avatar
leon_heller
XCore Expert
Posts: 546
Joined: Thu Dec 10, 2009 10:41 pm
Location: St. Leonards-on-Sea, E. Sussex, UK.
Contact:

Post by leon_heller »

Inputs are 5V compatible, see the data sheet.
User avatar
Woody
XCore Addict
Posts: 165
Joined: Wed Feb 10, 2010 2:32 pm

Post by Woody »

leon_heller wrote:Inputs are 5V compatible, see the data sheet.
Only XS1-G devices have 5V tolerant inputs. XS1-L parts have a maximum input voltage of 3.6V (~3.3+10%).

As Leon says, check the datasheets.
User avatar
leon_heller
XCore Expert
Posts: 546
Joined: Thu Dec 10, 2009 10:41 pm
Location: St. Leonards-on-Sea, E. Sussex, UK.
Contact:

Post by leon_heller »

I checked the data sheet I had for the XS1-L1, and that gave 5.5V as the maximum. The latest version gives 3.6V.

A resistor should be OK for the XS1-L1, I've seen one used with other devices.
User avatar
skoe
Experienced Member
Posts: 94
Joined: Tue Apr 27, 2010 10:55 pm
Contact:

Post by skoe »

Thanks!

There must be a reason they corrected it down to 3.6 V in the latest revision :) I'll add another resistor per pin to build a voltage divider, just to be on the safe side.
Post Reply