Hello,
When I use to WEBENCH Design simulated TPS54478 load transient simulation ,I find load transient result is poor .as below picture1.but for Bode plot result is good(Gain margin is -33.05) ,as below picture 2.
I don't why so ,could you help to analysis it and how to improvement it? attached file is WEBENCH Design schematic. thank you
Picture 1
picture 2
Hello Wenjun,
I was able to reproduce the issue you found on Webench.
My suggestion would be to use PSpice for TI.
You can request the software here
https://www.ti.com/event/docs/accesseventaction.tsp?actionId=3228
And this is the transient model for PSpice:
https://www.ti.com/lit/zip/slvmae8
This is the load transient with the following conditions:
Vin 3.3V
Vout 1.1V
Iout 0.1 to 1.2A
Rise/Fall times 12uA
The schematic I used was the following:
and the simulation profile:
Let me know if this helps to evaluate your design.
Best regards
Nelson
Hi,Nelson
I try to start a simulation for TPS54478 ,appear a error,why is it? thank you
Thank you for you kingly support ,Nelson
Below is my schmatic picture ,please check it
Hi Wenjun,
Thanks for the screenshot.
For your simulation, you would have to make your current page "root" (see the blue frame behind the icon? you can set it to a page by right clicking and selecting "make root"). I see the current root is Startup in your sim and it should be the SteadyState page.
Try to make your modifications on that Steadystate/PAGE1; it is more convenient than setting up a new page. Before simulating, make sure that your current simulation profile is Steadystate-trans:
Best regards
Nelson
Thanks ,Nelson
now simulation is ok ,and belwo is my simulation schematic and result(result is 1.039-1.142V, overtake my spec,1.1V requirement is 1.07V-1.17V).For TPS54478 ,how to do imprvoment it ?
Besides,for Bode plot simulate ,how to do it when use this tool?and ,WEBENCH bode plot simulation result whether is correctly ?
thank you
