RE: eQADC operation on MPC5554

"Dobbin Allan-r11834" <[email protected]> Tue, 14 Nov 2006 11:33:32 -0700

Newsgroups	gmane.comp.hardware.motorola.microcontrollers
Message-ID	<4147ED8B92A864498825C07E53594E4A01B67700@az33exm20.fsl.freescale.net>

What do you have connected to the REFBYPC pin?  You should only have a
100nF cap to gnd, not a resistor.  See EB643 - the resistor was only
required on very early revs of silicon.
 
- Allan

________________________________

From: [email protected] [mailto:[email protected]] On Behalf
Of JVB1_wow
Sent: Tuesday, November 14, 2006 11:37 AM
To: [email protected]
Subject: [MPC500] eQADC operation on MPC5554



Hello,
I am designing a system with the MPC5554 micro-controller. We are
planning on using the eQADC. Checkout of the prototype hardware shows
a large offset voltage of around -0.900V. The measured data in
perfectly linear just offset by this bias. Anyone seen this before? 
Thanks.

Joe



 


[Non-text portions of this message have been removed]