• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 50 subscribers
  • Views 692 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.

LM675: Thermal tab screw

Mark Guastaferro
Genius 11095 points
Part Number: LM675
Other Parts Discussed in Thread: OPA549

Would there be a recommended torque requirement for a mounting screw that attaches to the thermal tab of the LM675 (TO-220 package)? 

  • 0
    TI__Expert 5830 points

    Hello Mark Guastaferro,

    I don't believe there is any data for a torque requirement on the LM675 thermal tab. This is not a typical measurement for our device.

    Best regards,

    Errol Leon
    Texas Instruments
    Precision Amplifiers Application Engineer

  • 0
    TI__Guru* 93105 points

    Hi Mark,

    Your question regarding the recommended LM675 screw mounting torque reminded me of information that I had seen for the OPA549, which also uses a plastic, flange-mount TO-220 package. There is a pin count difference between the LM675 and the OPA549, but I think the general torque guidelines can be applied to the LM675.

    See the attachment for the details.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

    OPA549 Mounting Recommendations.pdf

  • 0 in reply to Thomas Kuehl
    TI__Guru* 93105 points
    Hi Mark,

    One of my application's colleagues who was part of the original National Semi team sent me this comment to my earlier response, "I recall I was told 10-12 ft/lb for TO-220’s. After 10 is diminishing returns and the possibility of distorting the tab and cracking the epoxy.."

    Since they developed the LM675, I would go with that recommendation.

    Regards, Thomas
    Precision Amplifiers Applications Engineering