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UCD9224 vs TPS40428 for 60A FPGA power supply

Other Parts Discussed in Thread: TPS40428, CSD95378BQ5MC, UCD9224, PMP9475, UCD9246, UCD9248

I have used UCD9224 in the past and noticed the Ultrascale reference design uses TPS40428 with CSD95378BQ5MC integrated High/Low side FETs.  I would like to have one controller for 3 FPGA voltages (60A@.9V, 15A@1V, 8A@1.2V) but not sure if better to control with device like USCD9224 or do high current with TPS40428 and lower currents with PS544B20 (like reference design).  Space and efficiency are key.

Thanks!

  • Hi Jay,

    I got this thread moved to the correct forum for these parts. One of our experts should be able to help from here with this.
  • It should be feasible to use UCD9224 with CSD95372B, but such a reference design does not exist so far. If your schedule allows, I can provide support to guide you through the design.   

    The major difference between CSD95372B and UCD74xxx is the current sensing signal. UCD74xxx’s current sensing signal is the averaged current signal, whereas CSD95372B’s current sensing signal is sawtooth instantaneous current signal. Therefore a filter is required to derive average current from CSD95372B.

    I cannot comment on TPS40428 or PS544B20.

    Thanks,

    Zhiyuan

  • I think there was an error in your initial question (which I corrected), it indicated UCD9224 with CSD95372 in the Xilinx Ultrascale reference design but the PMP9475 uses the TPS40428 with CSD driver/mosfet stages.

    UCD9246 would be the correct offering if you were looking to control the three rails with one controller, it can control up to 4 rails with up to 6 phases. The 60A rail would likely consume 4 phases (3 used, 1 leftover) then each of the other two voltages would consume 1 phase.

    UCD9248 (4 rails/8 phases) may be required if you ever needed to increase the current of the 20A rail much higher as the leftover phase on the UCD9246 (from the 60A rail) could not be used with the single phase rails (A and B phases can not be split between rails).

    No direct comparison has been done between these two components because they each have there own unique attributes, at least from the UCD side of the business.

    You would likely get additional comment on the TPS40428 on the Non-Isolated Dc-DC Forum, the Digital Power Forum is mostly dedicated to the UCD products although the other business unit will sometimes peruse this forum for their PMBus enabled analog controllers.