I verified yesterday that it is happening, and that it's not just temperatu=
re.  On external crystal a pin toggle based on a timer is dead constant.  O=
n internal RC, applying torque to the board wobbles the oscillator like a t=
heremin.


-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of=
 Sean Breheny
Sent: Thursday, November 2, 2017 4:47 PM
To: Microcontroller discussion list - Public.
Subject: Re: [PIC] [EE] Internal RC sensitive to PCB flex?

I don't know about documentation but I have seen this before but I cannot r=
emember whether it was with a 16F88 or dsPIC24. I noticed it only when I ap=
plied pressure directly to the package of the chip, though. I would suspect=
 that anything which applies pressure to the die will change the value of r=
esistors and capacitors on the die.



On Thu, Nov 2, 2017 at 5:01 PM, Van Horn, David < david.vanhorn@backcountry=
access.com> wrote:

>
> Is there any documentation on sensitivity to PCB flex when using the=20
> internal RC?
> I have seen this on SAM7 chips and I think it's happening on a 24F chip.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345 x110
> email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@
> backcountryaccess.com>
>
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive=20
> View/change your membership options at=20
> http://mailman.mit.edu/mailman/listinfo/piclist
>
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