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.

LM26LV DAP

Other Parts Discussed in Thread: LM26LV, LMT87

The datasheet of the LM26LV states that the DAP pad can be left floating or connected to GND. Is it internally electrically connected to GND? If not, what is the maximum voltage in respect to pin 2 GND that can be applied to the DAP pad?

  • Hi Cornelius,

    The DAP pad on the LM26LV is not internally connected to GND. The maximum voltage applied to the DAP pad should be 0V.

    -Michael Wong
  • Hi Michael,

    the reason I'm asking is that I want to measure the temperature of a FET and for best thermal conductivity the DAP should be soldered directly to the FET's drain copper area. This area is at 24V though. So it looks like this is not possible?

    -Cornelius
  • Hi Cornelius,

    What is your application? Also, are you only interested in measuring temperature and not using the comparator functionality of the LM26LV? If you are only measuring temperature then we can recommend an alternative part which has better performance and can be glued/placed near the FET. Does this FET also have a heatsink?

    -Michael Wong
  • Hi Michael,

    The FETs are used in 3-phase motor control and do not have a heatsink (i.e. they use copper area on the pcb for cooling). The idea is to use a temperature sensor which has a good thermal conductivity to this copper area to have a fast response time. We plan to use the comparator as well, but which parts would you recommend (even without internal comparator)?

    -Cornelius

  • Hi Cornelius,

    Since the PCB itself is used to cool the FET any of our surface mount temp sensors will work fine. I can recommend our analog output sensor the LMT87 as a possible candidate for this. The LMT87 detects temperature best through its ground lead which means it will effectively measure the board temperature. For best thermal measurements, place the LMT87 as close as possible to the copper area on the PCB without being exposed to the 24V on the FET drain lead.

    Let me know if you have any other questions.

    -Michael Wong