TPS54526: Inductor value selection for TPS54526

Nanjunda M

Expert 2485 points

Part Number: TPS54526

Hi,

I'm using TPS54526PWP in my design.

I'm using it to generate 1.35V and 1.8V from 5V.

Please find the attached schematics for reference.

My question is whether I can use 2.2uH in place of 1.5uH inductor (output) as suggested in the datasheet ?

What will be the effects of 2.2uH instead of 1.5uH ?

Please let me know ASAP.

over 8 years ago

0 Vincent Zhang(BSR) over 8 years ago

TI__Expert 4795 points

Hi,

Increase the inductor will reduce the current ripple, so will increase the efficiency. As the trade off, the 2.2uH inductor cost is a little bit higher than 1.5uH. Meanwhile, increase the inductance will also change the double-pole of buck converter to a lower frequency and impact the circuit loop performance.

My conmputer has something wrong with WEBENCH today, and I will run a simution and double check the loop performance tomorrow.

Regards, Vincent

0 Vincent Zhang(BSR) over 8 years ago

TI__Expert 4795 points

Hi,

TPS54526 don't release loop performance of WEBENCH.

I run a load transient test with TINA@1.35V out with 0.1A-5A, SR=5A/us, the results are as below. Both inductance are ok, but seems 1.5uH would have better load transient performance.

Lf=1.5uH

Lf=2.2uH

Regards, Vincent

0 Nanjunda M over 8 years ago in reply to Vincent Zhang(BSR)

Expert 2485 points

Thanks for the inputs.

Regards,
Nanjunda M

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TPS54526: Inductor value selection for TPS54526