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TPS54228: Use TPS54227DDAR to replace TPS54228DR

Part Number: TPS54228
Other Parts Discussed in Thread: TPS54227,

Hi team,

Currently customer’s TPS54228DR is facing shortage problem and they want to replace it with TPS54227DDAR. As you mentioned, the difference is that TPS54227DDAR has thermal pad.

  • Is the thermal pad be internally connected to GND pin?
  • If customer don’t want to change the PCB, can the thermal pad of TPS54227DDAR be left float?
  • If we keep the thermal pad of TPS54227DDAR float, will its power dissipation ability the same as TPS54228DR?

Thanks!

Br,

Nison

  • Hi Nison

    Amod is looking into this and will feedback to you soon.

    BR

    Ruby

  • Hi Nison,

    We are discussing this via email as well so we can continue there.

    For future reference, below are the answers:

    Please note TPS54227 has FCCM compared to PFM operation of the TPS54228 so efficiency at lighter loads with the TPS54227 will be lower compared to that of TPS54228. The transition point to PFM will be when the inductor current reaches zero and this will happen when half the inductor ripple is greater than the output current requirement.

     

    • Is the thermal pad be internally connected to GND pin?

       No it is not and can be left floating. However, for improved thermal performance, it is recommended to connect the thermal pad to GND.

    • If customer don’t want to change the PCB, can the thermal pad of TPS54227DDAR be left float?

       Yes it can be left floating. To achieve good thermal performance, it is recommended to connect the thermal pad to GND.

    • If we keep the thermal pad of TPS54227DDAR float, will its power dissipation ability the same as TPS54228DR?

             If the thermal pad is not soldered to the board, the DDA package is essentially the same as the D package. To achieve good thermal performance, it is recommended to     connect the thermal pad to GND.

    Thanks,

    Amod