LTC4020 Inductor Current

I'm playing around with the Demo Circuit 2134A. I've noticed that the top and bottom sense resistors are 2mΩ. Wouldn't this equate to an inductor current of 25A (50mV / 2mΩ)? How does the inductor current relate to the max output current?

Parents Reply
  • +1
    •  Analog Employees 
    on Mar 1, 2021 7:53 PM 1 month ago in reply to Nicknails

    Let's see.  The demo board is rated for 8A out, VINMIN=15V, VOUTMAX=28V.  That corresponds to a boost ratio of 1.87, so under those conditions the average inductor current will be 8*1.87=14.9A assuming 100% efficiency, greater than that in reality.  3mΩ resistors would limit average inductor current to 16.7A, and there wouldn't be much headroom for dynamic load changes.  So, 2mΩ seems like a good value.  I can only assume the DC2134A designer engaged in similar thinking.

Children