WEBENCH® Tools/TPS54020: TPS54020 Webench simulation fail

Part Number: TPS54020

Tool/software: WEBENCH® Design Tools

I use webench to simulate the TPS54020's phase margin and gain margin on my application.

My input is 12V, and when output is 3.9V/4.29A or 1.8V/2.28A the webench runs normally, but when output is 2.4V/2.48A, webench says it cannot simulate.

It seems that webench is related with output voltage. If I change to 2.41V or 2.39V webench runs with a new parameter "coutx."

It happened this week, last week didn't happen.

Does server go wrong?

3 Replies

  • Hi James,

    I'm asking the WEBENCH team to help check why it cannot create a design. I will update you when I know more.

    Best Regards,

    DC/DC Power Applications Engineer

  • In reply to Anthony F:

    Hi Anthony,

    Today webench seems normal again, but in the circuit is a new cap Coutx. I don't see Coutx at 3.9V, 1.8V, and 2.4V simulated before.

    What's difference between Cout and Coutx?

    BTW, Coutx doesn't connect with circuit, what's wrong with it?

  • In reply to James Chiu:

    Hi James,

    Coutx is added in when WEBENCH selects mixed type output capacitors. It may do so for size or costs reasons. The first Cout is typically something with higher ESR like an aluminum electrolytic, tantalum, sp-cap, etc. The second one is typically a low ESR ceramic capacitor.

    Coutx not being connected is just an image error. It is not important for it to be connected in this view within WEBENCH. It is only important for it to be connected when using the Sim section within WEBENCH. This misalignment should still probably be corrected. I'm going to check if someone on the WEBENCH team has seen this post yet.


    DC/DC Power Applications Engineer