• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 1044 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TPS7A61-Q1: Alternative component without thermal shutdown.

vn_pr
Prodigy 40 points
Part Number: TPS7A61-Q1
Other Parts Discussed in Thread: TPS7A6650H-Q1

Hi, 

I am looking for an alternative to the LDO TPS7A61-Q1 ( TO-252 package) without the thermal shutdown option. Vin = 15V and Vout = 3.3V max current = 35mA

Want to use it on a high temperature application and am worried this would trigger a shutdown/reset. 

Any help would be appreciated. 

  • 0
    TI__Mastermind 23361 points
    Hi Vineet,

    According to the datasheet, the Rja of this device is 26.9 C/W(The thermal data is based on JEDEC standard high K profile JESD 51-5. The copper pad is soldered to the thermal land pattern. The correct attachment procedure must be incorporated.). The power for your application is (15 - 3.3) x 0.035 = 0.41watts. The temperature change would be 26.9 x 0.41 = 11C

    With proper layout, you may see an estimated temperature rise of 11 degree C. This temperature will be added on top of your ambient temperature. As long as your ambient temperature plus the added 11 degree C is less than 150C, the part would function normally. Again, this estimation is done with JEDEC standard, the real thermal performance on your board would vary.

    Regards,
    Jason Song
  • 0 in reply to Jason Song
    Prodigy 40 points

    HI Jason,

       Thank you for your reply. I want to use this device for a 150C profile, have tested it for long duration upto 150C and it has given us good results. No thermal shutdown was observed during testing.

    The concern is that since the thermal shutdown is around 165C, seems its right on the edge. Thus wanted to see if there is an alternate without thermal shutdown feature we could use.

  • 0 in reply to vn_pr
    TI__Mastermind 23361 points
    Hi Vineet,

    The device is being verified, qualified and rated to 150C junction temperature. Even the devices did not enter thermal shutdown, once beyond 150C, the devices have been stressed beyond the maximum rated temperature and this may reduce lifespan of the device and cause permanent failures.

    Most LDO will have thermal shutdown to prevent permanent damage due to short circuit or other non regular conditions. Let me do some research to see if we have a device similar to TPS7A61-Q1 but will run at 165C. Please allow some time for the investigation.

    Regards,
    Jason Song
  • 0 in reply to Jason Song
    TI__Mastermind 23361 points
    Hi Vineet,

    Just a follow up. Upon checking, TPS7A6650H-Q1 is one of the few LDO that can go 165 but the output is 5V. We don't have 3.3V LDo that can work at 165C.

    Regards,
    Jason Song