Tool/software:
Hi,
My customers have a question regarding LM3409-Q1's ripple.
With the polarity swap, there is a minimum current ripple need to maintain, however the customers also would like to have a smaller current ripple on the inductance. Now for a 6A average current design, they want to have a smaller than 600mA ripple, which lead to the Rsns>24mV/600mA=40mohm according to equation 11 below. While with a 40mohm Rsns, the current when triggering Vcst is only 246mV/40mohm=6.15A, this might be too small for a peak current to have 6A average current. But a smaller Rsns lead to a higher current ripple which must to maintain.
This problem troubled my customers to achieve a design with 6A average current and smaller than 600mA ripple.
- Do you have any suggestions on achieving a relatively smaller current ripple with LM3409-Q1?
- The 24mV in equation 11 and should came from the offset of internal comparator, customers would like to know can we provide like a typical value (or offsets’ distribution data) of the offset that smaller than 24mV, which that in most of the time the ripple can meet the requirements and the ripple is smaller at the same time?
BR,
Manu
