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LTC3728's Parallel Operation


I am considering the LTC3728.
Is it possible to configure a parallel output using the LTC3728?
I would like to use it in the configuration shown below.


Best Regards,

  • Hello,

    Yes, the LTC3728 can be configured for a single output, dual phase converter. The data sheet does not show examples, but this has been done before. When paralleling phases, make these connections:

    • Tie VOUT1 to VOUT2
    • Tie the VOSENSE1 pin  to the VOSENSE2 pin
    • Tie the ITH1 pin to the ITH2 pin
    • Tie the RUN/SS1 pin to the RUN/SS2 pin

    An example is shown below:

    If the 5V input will drop below ~4.7V during normal operation then tie the VIN and INTVCC pins together and tie the combined pins to the 5V input with a 1Ω or 2.2Ω resistor. Since INTVCC supplies the gate drive voltage for the top and bottom MOSFETs, this will ensure the MOSFETs have a sufficient gate drive voltage.

    More recent dual phase / dual outputs parts to consider are the LTC3850, LTC3855, LTC3869, LTC3875, LTC3838/-1/-2 and others. Single output dual phase controllers to consider are the LTC3856 and LTC3839. 

    Best regards,