• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 40 subscribers
  • Views 594 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.

TIDA-00120: MOSFET HEATING ISSUE IN REFERENCE DESIGN TIDA-00120 BATTERY SIDE MOSFET CSD18502Q5B TEMP. 130 DEGREE C

Mitesh
Prodigy 190 points
Part Number: TIDA-00120
Other Parts Discussed in Thread: CSD18502Q5B, , CSD18502KCS

 I am working of your Solar charge controller reference design TIDA-00120. I have designed the PCB, mount the components and program the MCU according to your site instructions. All thing are work properly but when i have test it on highest capacity of charge controller of 19.5A at 12.5v on battery the Q6 mosfet CSD18502Q5B than present for battery reverse protection is heats at 125 degree C when environmental temp. is 28 degree C. How can i reduce the temp. of this mosfet.

I have also use it on 15A configuration but there is heating around 95 degree C, which is not match the thermal calculation of this mosfet. 

  • 0
    TI__Expert 3860 points
    Hi Sanjay,

    There can be about 1 - 1.3 W power dissipation in this MOSFET while 20A current is passing through it. We used 105u Copper for this board to get the temperature under control. What is the Copper thickness you are using? If the Copper is insufficient, you can solder extra heat sink to the device pad on the top side of the board. A small copper plate can act as a heatsink.

    Regards,

    Salil
  • 0 in reply to Salil
    Prodigy 190 points

    Sir, I have use 35u PCB for this board. Heat sink with this SMD mosfet is not possible in production. Can i replace these SMD mosfets with through hole mosfets, if yes than please suggest me the part number. 

  • 0 in reply to Mitesh
    TI__Expert 3860 points

    Sanjay,

    With 35u Copper, there could be gate drive issues with the switching MOSFETs as well (due to the increased inductance of gate drive path). The minimum suggested is 70u. Please use 70u Copper for reliable operation of the circuit.

    If you want to use a through-hole package the CSD18502 is available in "KCS" option, which is a TO-220. The full part number is CSD18502KCS. However, you will still need a heatsink with this package as well since 1W cannot be dissipated in it.

    Regards,

    Salil