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DCR010505: DCR01 Series, 1W DC/DC Converter overheats

Kevin Valentine
Prodigy 20 points
Part Number: DCR010505


We have had a fairly recent set of field failures of the DCR010505U due to the part overheating. The first question I have is has anything in this part changed within the last 4 years? We have been using the part since 2010 and haven't had any problems until recently. 

  • 0
    TI__Genius 11930 points

    Hi Kevin,

    No changes. Can you please provide additional details on failures observed.

    Thanks. 

  • 0
    Prodigy 20 points

    Hi,

    We are using two of these DCR010505 converters on one circuit board, and the product has been going to customers since 2010. We have not had any issues with field returns until about 2024 and now there have been a rash of field returns since 2024. We notice that one or both converters run very hot (about 110°C) and fail. The application is industrial control used at < 85°C. Last year we changed the MOSFET (Q63) that is attached to the SYNC pin to a lower capacitance device (~4pF), but these are not out in the field yet.I can provide circuit diagram but can't seem to paste it in this message.\

    Thanks,

    Kevin

  • 0 in reply to Kevin Valentine
    TI__Genius 11930 points

    Hi Kevin,

    Thanks for sharing the details.

    What is the ambient temp while device reaches 110deg and fails. Does the device restarts back once the temp is normal or it is completely damaged and needs replacement. If it is completely damaged can you please check the pin impedance vs Vcc & Gnd pins. Is there any change in pcb design or operating temperature with respect to earlier condition?     

    Please upload schematic using Insert tab. 

    Thanks. 

  • 0 in reply to Shinu.V.Mathew
    Prodigy 20 points

    Hi Shinu,

    Attached is one of our Technical Reports from last year that describes our findings. We have since changed the MOSFET to a lower capacitance part (~4pF) but these are not out in the field yet.

    TR-2024-26C.pdf

    Thanks,

    Kevin

  • 0 in reply to Kevin Valentine
    TI__Genius 11930 points

    Hi Kevin,

    Thanks for sharing the data and report. 

    Can you please check and confirm the device is working independently without frequency sync function and the temperature rise is normal?

    Is this temperature rise and failure is observed only when the sync function is used and how many devices are connected together with sync function. 

    Thanks. 

  • 0 in reply to Shinu.V.Mathew
    Prodigy 20 points

    Hi Shinu,

    We are only using the SYNC pin to provide a 20ms delay for the Vout. We can observe what happens when we disconnect this circuit from the SYNC pin. What is a normal temperature rise for this 1W device, assuming we are consuming close to 1W?

  • 0 in reply to Kevin Valentine
    TI__Genius 11930 points

    Hi Kevin,

    For DCR010505 Theta JC is 26°C/W and Theta JA is 61°C/W.

    Thanks.