WEBENCH® Tools/TPS54620: Phase margin of bode plot sim and operating values

Yuto Sakai

Part Number: TPS54620

Tool/software: WEBENCH® Design Tools

Hi,

I attach the simulation result of bode plot.
TPS54620_Bode plot sim.pdf
When checking phase margin of bode plot and operating values, I got the following results.
・phase margin (bode plot sim): 62.724 deg
・phase margin (operating values): 27.005 deg
The values do not match, which value should I refer?

Best regards,
Yuto Sakai

over 6 years ago

0 JohnTucker over 6 years ago

TI__Guru**** 191445 points

Sakai-san,

Can you share your Webench deign with me? Share it to j(dash)tucker(at)ti(dot)com. We can examine it in detail.

0 JohnTucker over 6 years ago in reply to JohnTucker

TI__Guru**** 191445 points

Sakai-san,

I recreated it and here are the Bode plot results(Fco = 7.03 kHz and PM = 64.62 deg :

0 Yuto Sakai over 6 years ago in reply to JohnTucker

Mastermind 6100 points

Hi John-san,

I shared my design with you.
This circuit quotes the customer's design constants.
I want to judge whether the constants around the COMP pin are satisfactory.
Please tell me whether the bode plot outputted in the simulation is correct or phase margin in "Operationg Values" is correct.

By the way, I entered customer's constant from Re-comp's "Manual" and calculated it,
but it did not become the same as your result.

Best regards,
Yuto Sakai