Question about formula for getting a sense register & inductor DCR of LTC2977


My customer asks some questions about getting a sense register & inductor DCR of LTC2977.

They will monitor a current of DC-DC Power  and use Inductor DCR Current Sensing Circuit. 

Please refer Page 83 of LTC2977.

Q1) Would you let me know the meaning of  "2≠" in second formula for getting CCM2 ?

      They say that they can't understand the exact  meaning of "2≠" in formula for getting CCM2.

Q2) If you have, would you explain the methods to get values of CCM1 CCM1 CCM1 & CCM2  easier?

       Please help them.



  • +1
    •  Analog Employees 
    on Jun 16, 2021 5:42 PM

    Hi Se-woong,

    The character in the equation is pi (3.14).  Sorry for the confusion, I will ask to get this fixed.

    The first RC stage attempts to cancel the zero created by the inductor LR.  The second stage creates a pole at one-tenth the switching freq. of the converter.