SAM3 rc oscillator temperature drift

Discussion around product based on ARM Cortex M3 core.

Moderators: nferre, ncollot

cybersam
Posts: 2
Joined: Fri Sep 02, 2011 7:04 pm

SAM3 rc oscillator temperature drift

Fri Sep 02, 2011 9:51 pm

The documentation on the temperature drift of the RC oscillator for the slow and fast clock seems to be missing. Namely what is the frequency error vs temperature with these parts.

In portable applications the device can be subject to considerable temperature extremes and knowing this temperature drift (and how it affects the operation of the system the device in) would be helpful.

Thanks in advance.
CptTitanic
Posts: 871
Joined: Sat Oct 30, 2010 6:04 pm

Re: SAM3 rc oscillator temperature drift

Sat Sep 03, 2011 1:58 am

Probably because it's not tested/characterized over temperature, and hugely process dependent.

You'd presumably therefore have to run your parts over temperature to characterize them individually.
cybersam
Posts: 2
Joined: Fri Sep 02, 2011 7:04 pm

Re: SAM3 rc oscillator temperature drift

Tue Sep 06, 2011 3:52 pm

[quote="CptTitanic"]Probably because it's not tested/characterized over temperature, and hugely process dependent.[/quote]
Thanks for responding

The process generally doesn't change unless there is a hardware revision so once characterized it should be fairly consistent. Mostly it's a 'does it drift greater than +-1% over it's rated temperature' is my real question. But knowing how much it can drift and over what ranges is rather helpful (I've found). I have to do this with any and all oscillators used in industrial applications (they aren't used in a temperature controlled environment).

[quote="CptTitanic"]You'd presumably therefore have to run your parts over temperature to characterize them individually.[/quote]
I hate doing those kind of tests, just setting up such a test can require a considerable amount of planning (monetary units as well) to be correct, and one would need to have enough samples as well (remove statistical anomaly issues).

Most people I guess don't see the value of knowing what an RC oscillator does over temperature. However if you buy an oscillator it comes with that data (or the parabolic coefficient if a crystal). I was hoping that the RC oscillators had been treated just like any other oscillator and tested for drift over temperature. That can become an annoying issue, when the temperature is guaranteed to vary, without much effort on the unfortunate designers part.

Anyhow thank you for apprising me of what there was.

Return to “SAM3 Cortex-M3 MCU”

Who is online

Users browsing this forum: No registered users and 5 guests