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  • TI Thinks Resolved

TPS55340: TPS55340 Heating Problem

Prodigy 190 points

Replies: 12

Views: 224

Part Number: TPS55340

Hi, I'm using TPS55340 for boost converter 18V-23V to 24 V and 3A. But it's heating while drawing 1.5A. Why? Datasheet says it can handle 5A but even 1.5A it is getting hot not only TPS55340, also diode and inductor. I build nearly same circuit on webench which is below. There are only 2 difference between my design and webench. Diode 5A 60V(Webench says 10A 200V) and RCOMP 3.3K(Webench says 3.24k).

And also my PCB is 2 layer, One layer for components and other layet full ground. 

  • Dear Sir,

    It depend on your layout. Heating is a normal phenomenon for the 1.5A output current. Could you please share the layout file with us?

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Helen chen:

    Hi, 

    There is my PCB and SCH file. Boost_PCB&SHC.rar

  • In reply to Foras:

    Will feedback to you tomorrow!

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Foras:

    Dear Sir,
    I checked your layout. The power trace(Vin pin to inductor, inductor to diode and the diode to the Vout) is very very thin, these traces should be thick and short. Or there will be thermal problem .P lease follow the datasheet and the TPS55340EVM board for the layout.

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Helen chen:

    Hi Helen,

    Thanks for quick reply.
    Vin's width is 0.5 and Vout's width is 0.8, what should i do their width ?
    And all my other components does not make any problem about heating right ? Is it all about traces ?

    Best Regards
  • In reply to Foras:

    Dear Sir,

    The hottest component will be IC, inductor and the diode. other component will not hot since they are not the power component.  Please refer to the datasheet and the EVM board to pour more coppers for these power components.

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Helen chen:

    I made thicker cables but still same result. It is still hot. I also have TPS5340EVM-017 and same load, only diode gets hot. I do not understand i made same circuit and nearly same components, and one layer ground but it gets hot.
  • In reply to Foras:

    The component dissipate thermal through the pad, so the big copper on the pcb board helps. And the cable is different with the pad, it is less effective for the power component's thermal dissipation.

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Helen chen:

    2727.Boost.rar

    Hi Helen,
    This is my new design can you check it?
    What do you think does it get hot ?

    Best Regards,

  • In reply to Foras:

    Dear Sir,

    I made a small change based on your pcb. the diode to the IC, then to the Cout loop should be very small.

    By the way, please redesign the pcb lib. Its thermal pad should be defined as pin 17 and it should be connected to PGND. Your current version lib the thermal pad can't help to dissipate the thermal because it can't conduct the heat out. pcb2.zip

    Best Regards,
    Helen

    Boost DC/DC Solution

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