• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 83 subscribers
  • Views 271 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320LF2407A: Absolute rating of VREFHI input for internal ADC

PinkCrapeMyrtle
Intellectual 1170 points

Part Number: TMS320LF2407A

What affect on the MCU would occur if the VREFHI input for the internal ADC is a negative voltage (~ -1 to -2V in amplitude)?  Would this damage the device?

 

  • 0
    TI__Guru* 86290 points
    Since this is outside the tolerance of the VREFHI input range, the ADC would be non-functional in this case.

    More importantly, as you mention, is if any damage will occur to the device.

    The ESD clamping diodes are rated to +/-20mA, so it is really dependent on the max current whatever is connected to VREFHI can output. If the 20mA is exceeded the device will be damaged, and cannot be assume reliable after this event(even if the device "appears" functional to some degree).

    Continued operation at/near 20mA will reduce the lifetime of the device as well.

    The above assumes that the VREFHI signal is the only pin that is exposed to the -1V - -2V, if there is more than one pin there is a cumulative effect up to the 20mA that must be observed as well.

    Best,
    Matthew