Hi Team,
What is recommended technique for LM25141-Q1 stability measurement, where Vout is 3.3V fixed (FB connected to VDDA)?
How to inject and measure loop response?
Piotr
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Hi Team,
What is recommended technique for LM25141-Q1 stability measurement, where Vout is 3.3V fixed (FB connected to VDDA)?
How to inject and measure loop response?
Piotr
Hello Piotr, you need to break the trace from vout to FB and add an excitation resistor. Value of this resistance is dependent on excitation amplitude. I usually use 10-50 ohm.
So in 3.3Vout/5Vout fixed application external FB path still has to be added just for stability measurements.
I understand after stability measurements done, application can go back to internal FB divider (leaving external FB divider not populated or so)
Can you see any issues with that approach?
Hello Piotr,
You need the exciation resistor in the feedback path.
No, I see no issue.