TPS54418A: Question on parameters for small signal model for loop response

Jonathan Tillack

Part Number: TPS54418A

Hello,

I would like to run a simulation for the loop response of the TPS54418A to investigate some stability issues we are seeing.

The datasheet shows the small signal model in Figure 31. I don't see recommended values for the COUT(ea) and ROUT(ea) in the datasheet. What values should be used?

Thanks for your help!

over 2 years ago

0 Chris Glaser over 2 years ago

TI__Guru**** 150660 points

Hi,

These are internal values to the device that are fixed and not needed for any calculations. They are shown in the figure for completeness. The EA has a (very high) limited gain and a (very high) limited BW. Your C2 and R3+C1 compensation network dominate over the internal characteristics of the EA.

Figure 34 shows a 5 pF value for CoutEA, for example.

We also have average and transient models here: https://www.ti.com/product/TPS54418#design-tools-simulation

Thanks,

Chris

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TPS54418A: Question on parameters for small signal model for loop response