• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 32 subscribers
  • Views 217 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.

DRV401: VAC located close the relay - magnetic field effect from the relay to the VAC.

Shlomi Alk
Prodigy 10 points
Part Number: DRV401

Hi,

I located the VAC (current sensor) close to relay (~0.3cm) and I have constant magnetic field effect on the VAC when I close the relay.

I tried to connect the DEMAG pin to manual switch and do demagnetization after the relay has closed, but it doesn't help.

the "easy" solution is to change my PCB design, can I solve it without to change the design?

thanks for your replay. 

  • 0
    TI__Mastermind 27715 points

    Hello Shlomi,

    Thank you for the question, and welcome to the E2E forum! Our engineers are out of the office for a long holiday weekend in the U.S. We will analyze and respond to your question when we return to the office tomorrow.

    Best regards,

    Ian Williams
    Applications Manager
    Current Sensing

  • 0
    TI__Mastermind 26485 points

    Hello Shmomi,

    The DEMAG will only demagnetize the core and will not eliminate any external magnetic field generated.  The closed relay will create and external field giving you a DC offset.  You could have a calibration factor for with relay energized and without it energized but you could have issues is the relay creates a large enough field.

    If the field is large enough you could magnetize the core and create a DC offset even after you remove the field causing you to have to DEMAG every time you switch the relay. 

     I do not see any other way of solving this without changing your PCB design for a more robust solution.