TPS5410-EP: Thermal Calculations

Ioannis Stamoulis

Part Number: TPS5410-EP
Other Parts Discussed in Thread: TPS5410-Q1, TPS5410

Hello,

I was going through the thermal calculations and I noticed that the Quiescent Current Loss formula doesn't seem right. I believe it needs the quiescent current added (typ: 3mA). Even so, there is a significant difference between the total calculated current and the one named Pic on WEBENCH (with TPS5410 or TPS5410-Q1, as the EP version is not supported). Could you please check the formula and let me know of the correct one? Thank you very much.

over 2 years ago

0 Marshall_Beck over 2 years ago

TI__Mastermind 35190 points

Hello Ioannis,

I believe those equation's do need some further refinining, but may be good approximates.

I would recommend you refer the to the TPS5410 webench design to obtain IC power loss, as , it is correlated against bench data.

0 Ioannis Stamoulis over 2 years ago in reply to Marshall_Beck

Prodigy 10 points

Hi Marshall,

Thank you very much for your quick reply. Unfortunately, this is not quite the answer I was looking for. The equation is incomplete, not unrefined.

I would check my calculations against webench results, so I can ensure correctness and present both as evidence. Without the correct equation, I cannot present a design for review based solely on the tool's results as they cannot be validated, at least by us. I hope you understand.

Thank you for your time.

0 Marshall_Beck over 2 years ago in reply to Ioannis Stamoulis

TI__Mastermind 35190 points

Hello Ioannis,

I understand.

If you have any concerns with webench I would advise correlating against EVM or the efficiency calculations contained in the datasheet.

To compute the IC power loss alone, you can factor out the conduction and core loss of the inductor (MSS1260-683) utilized for the measurements.

Conduction loss: LDCR*IOUT^2

Core loss: www.coilcraft.com/.../

Power management

Power management forum

TPS5410-EP: Thermal Calculations