Hello,
I am trying to design a SEPIC converter with the LM5022 using your WEBDESIGNER design tool. The basic specifications are these:
- Input voltage range: 15V-25V
- Output voltage: 24V
- Maximum output current 3.5A
The schematic proposed by the tool is the following: : https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=89E4A78AE1183FBA
My question is about the inductors. Specifically, it is the CMX1211Z181B-10. I have not made detailed calculations but I think it is oversized both in the value of the inductance and in the maximum current. Due to layout issues I can not use this component and the design tool does not provide me with another option.
In the LM5022 datasheet I could not find an example of calculating the inductors for a SEPIC converter (only for Boost Converter), so I followed your design guide 'AN-1484 Designing A SEPIC Converter'. Next the steps to size the inductors, I obtain the values of:
- Dmin= 49.6 %
- Dmax=62%
- L1 ripple current = 2.75A
- L1 = L2 = L = 22 uH
- The peak input inductor current is for L1 = 7.2A, and for L2 = 4.375A
Based on these values, I understand that the CMX1211Z181B-10 is an oversized component, right?
Because I can not mount a first prototype on a breadboard. Is this inductor SRP1265A-330M a good choice for both L1 and L2?
Thanks and best regards.
