• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 30 subscribers
  • Views 629 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TMP513 Question - Application Use case question

Dan Nitta Mackay
Intellectual 2560 points
Other Parts Discussed in Thread: TMP513

HI Dan,

I have a customer planning to use (Remote sensing) external transistor for PCB board temp monitoring as diagram below showed in Datasheet.

The customer couldn’t find transistor selection recommendation from datasheet.  Can you please provide transitor recommendations.

 

The customer would also like to know what is the impact if we didn’t have input filtering

 

Please help.

Sincerely,

Dan Nitta Mackay TSR Ottawa Canada

  • 0
    TI__Expert 4905 points

    Hi Dan,

    Sorry for the delay in responding. The recommended transistor is 2n3904 or 2n3906 - either will work well. The default n-factor setting would work so no adjustment required.

    Filtering is dependent on the PCB layout and noise coupling into the diode traces. The TMP513 includes series resistance cancellation and it can handle up to 1k ohm of series resistance on each diode trace. Place the filter as close as possible to the diode input pins. The maximum the differential filter capacitor can be is 2.2nF. Please refer to curves in the datasheet for effect on accuracy as there is a slight effect with no noise present in the system. If there is appreciable noise, the error caused by the noise would dwarf the effect of these components on their own.

    Noise usually causes a positive offset on the temperature reading.

    Take care,

  • 0 in reply to Emmy Denton
    TI__Intellectual 2560 points
    Thanks Emmy,

    I have shared your additional comments. Appreciate the feedback.

    Cheers,
    Dan