MSP430 ADC failure

Started by Thomas Montroy October 29, 2008
Hi All,

I'm running an MSP430F2618 (Rev E) with a 12 bit ADC. On one of our
prototype devices, the ADC has stopped working. As far as I can tell the
rest of the device works fine. The ADC works fine on all of our other
prototypes (with the same software), so the problem appears to be inside
this particular chip.

Has anyone seen a behavior like this before? This is the first msp430 that
I've seen that was damaged. Could ESD do this?

Any ideas would be appreciated.. Thanks.

-Tom

Beginning Microcontrollers with the MSP430

Yes,
I have seen failures on the f149 on multiple occasions.. You need to protect it agains esd as you would any other external connection.. The symptoms vary, I have seen some give consistently low readings to other that are totally dead..

--- On Wed, 10/29/08, Thomas Montroy wrote:

From: Thomas Montroy
Subject: [msp430] MSP430 ADC failure
To: m...
Date: Wednesday, October 29, 2008, 2:25 PM

Hi All,

I'm running an MSP430F2618 (Rev E) with a 12 bit ADC. On one of our
prototype devices, the ADC has stopped working. As far as I can tell the
rest of the device works fine. The ADC works fine on all of our other
prototypes (with the same software), so the problem appears to be inside
this particular chip.

Has anyone seen a behavior like this before? This is the first msp430 that
I've seen that was damaged. Could ESD do this?

Any ideas would be appreciated. . Thanks.

-Tom






Thomas Montroy wrote:
> Hi All,
>
> I'm running an MSP430F2618 (Rev E) with a 12 bit ADC. On one of our
> prototype devices, the ADC has stopped working. As far as I can tell the
> rest of the device works fine. The ADC works fine on all of our other
> prototypes (with the same software), so the problem appears to be inside
> this particular chip.
>
> Has anyone seen a behavior like this before? This is the first msp430 that
> I've seen that was damaged. Could ESD do this?
>
> Any ideas would be appreciated.. Thanks.
>

I don't know this particular one but I have seen a fair share of ESD
damage with the MSP430. If you need to get to the ground of it you could
try to configure the code so the ADC input is at another port pin. Apply
some voltage to that pin and vary it across the whole range while
comparing input values to what the MSP430 reads out. If it then works
your normal port pin has probably been zinged.

In case you need pointers on how to ruggedize this port post the schematic.

--
Regards, Joerg

http://www.analogconsultants.com/