TPSM365R3: Webbench efficiency deviation

Peter G.

Part Number: TPSM365R3

Hello,

I did a Webbench simulation of TPSM365R3FRDNR using the following parameters:

- Input 14 to 26V

- Output 8.5V / 0.2A

- User prefered frequency 1.9 MHz (Rt = 8.2 kOhm)

Webbench shows a resulting efficiency of >90% for all input voltages and output current >0.15A.

Now I measured my real application with a constant load of 0.17A. The efficiency started at 85.5% @14V and dropped linear to 74.8% @26V.

What is wrong here? Is there a bug in the Webbench model?

Regards, Peter

0 Andrew Kutzler over 1 year ago

Hi Peter,

The efficency recommended by webbench does seem off. I checked myself.

Also, the efficiency you are getting is around what I got when I qualified the part for 2MHz.

I'll report this to the webbench team.

Thanks,

Andrew

0 Peter G. over 1 year ago in reply to Andrew Kutzler

Hi Andrew,

thanks for confirming my presumption.

I think the results for input current and temperature rise are also affected from this bug. The results for TPSM365R3 (w/o 'F') seem to be right.

Regards, Peter

0 Andrew Kutzler over 1 year ago in reply to Peter G.

Hi Peter,

Understood. Thanks for finding this error.

Thanks,

Andrew

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