• ltm4646 no output voltage. Schematic help.

    There is no output voltage on both channels, but there is voltage on the output of powerGood. Could this be a consequence of a forgotten resistor on the Rfreq pin?
    I don’t understand how PG can be, but there is no output voltage.

  • RE: LTM4646 feedback divider

    Hi Mikee

    This RFB2 || RFB3 design has been my question.

    If we need 1.5V output on Vout2, can we use two 30K for RFB2 and RFB3 ? we notice that the values in datasheet Table 1:  40.2K||24.3K = 15.1K, equal to two 30K in parallel. I think RFB2 and RFB3 could…

  • Is there a parallel model for LTM4646 in LTPOWERCAD?


    Does a model for the LTM4646 in parallel configuration exist for the LTPOWERCAD tool?

    I am using three outputs in parallel and cannot get the appropriate response in my LTSPICE sims.


  • capacitance of SYNC pin of LTM4646 and LTM4622

    Hi there,

    we use 10 pcs of  LTM4646 and 10 pcs of LTM4622 on a big power system. System requires External Synchronization Clock (800KHZ) for all DC/DC.

    Now ONLY ONE sync clock 800KHZ is generated from FPGA, and feed to 20 DC/DC in daisy-chain topology. The…

  • LTM4646, LTM4622 and LT3070 Schematic help review

    Hi there,

    we newly import LTM4646, LTM4622 and LT3070 into our project for the frst time. To be careful, we would like to ask for asisting review. Insight of LT/ADI expert will be appreciated. .

    SCH as PDF attached, and Load conditions are text-noted nearby…

  • LTM4646: Thermal Resistance and Allowed Mechanical Pressure when mounting Heatsink


    We use LTM4646 for 3.3V/10A design. Estimated power dissipation on LTM4646 is about 4W. Two question.

    (1) We noticed there is three thermal resistance parameter: θJCtop = 12.6°C/W, θJCbottom = 1.8°C/W, θJB = 2.3°C/W, What the difference of…

  • LTM4646 Multiphase Operation


    I'd like to confirm the number of Multiphase of LTM4646.

    According to the data sheet page 11, Up to 6 phases can be cascaded to run simultaneously with respect to each other

    by programming the PHASMD pin to different levels.

    But on page 14…

  • How to connect SGND and GND pins in LTM4646 and LTM4622

    Hi there, 

    we use LTM4646 and 4622 , for layout ,some questions to consult. 

    In both datasheets, it mentions that " Use a separated SGND ground copper area for components connected to signal pins. Connect the SGND to GND underneath the unit ".…

  • RE: LTM4622 Schematic help review

    Thanks, Young, I would re-check this compensation RC network again.

    By the way, if you have time, could you please help take a look at this question, it is about LTM4646 Vout2=1.5V  and its feedback resistors value , This is the link, please see my latest…

  • How to compensate for loop response of poly-phase operation with any uModules?



    For example, when we design 8-phase operation with four LTM4678 how to check the loop response by Frequency Response Analyzer? 

    What about 4-phase operation with two LTM4646?