# What are the issues with using multiple inductors for a DC/DC converter?

I'm going to be designing a Buck Converter that will supply a max of 10A of current to an LED Strip (9V to 20V in, 5V out). Since I want to minimize the amount of EMI in the circuit, I want to use shielded inductors rated for around 26uH. But since the inductor would have to be rated for at least 10A (preferably 15A or higher), there aren't a lot of options to chose from. So instead, I was thinking of using two 13uH inductors in series so that I would have a larger variety of parts.

I understand that the math works out to where 13uH + 13uH = 26uH. But are there any real world issues that comes with using multiple inductors in a DC/DC converter?

• @MicroservicesOnDDD Throw in parasitic caps of different values in parallel with your inductors in simulation. Different for each inductor. Mar 6, 2021 at 20:31
• @DKNguyen -- Have done. Put 3 Taiyo Yuden NRS6010T100MMGF 10uH 1.1A 324mOhm SMD in series with 100p on 1st, 71p on 2nd, & 120p on 3rd. Ringing max 12mA. Doesn't seem to affect output. What should I be seeing? Mar 6, 2021 at 21:40
• I was just curious how much is too much is all. If the resonant frequency of the tank circuit matches one of the switching harmonics I would expect to see an increase in noise at that frequency. Just like with anti-resonance when mixing decoupling caps. Mar 6, 2021 at 22:03
• There is a good answer here: Is parallelling inductors a viable solution? -- yes, suggest trying a super-inductor, where it talks about a "super-inductor", an array of 2x2 (4 total) inductors that have the same inductance and resistance, but much greater saturation ability, because the currents are divided. In other words, each inductor actually has the same saturation limit, but because the currents are divided, a 2x2 array of the same inductor can handle twice the saturation current. Mar 7, 2021 at 0:02
• @MicroservicesOnDDD We need your winding polarity comment that was on the other question on here as an answer. Mar 7, 2021 at 20:14