Dear Team,

I am using this buck converter for one of my application.

Input voltage is 12V and output is 5V ,3A. During simulation what I observed is the output is taking almost 1.8s to reach it's final value.

Can you please tell me why it is happening like that.

Will this long settling time create any stability issues.

May I know how to improve the settling time.

Circuit Diagram,



Output Wveform


Regards
HARI

 

Change the load to a resistor. A current source is an unusual load that is affecting the operation.

 

I put a 1K resistor at the output instead of current source,but the response remains the same.

 

Don't see any obvious reason for that long response time.
Look at all the pin voltages to see if any also exhibit that same long time to achieve final value.

 

A bit of a longshot, but. . .
You have a decoupling capacitor on the EN input, which seems to have zener to ground which is the reference. The application circuits have no capacitor on the EN pin.
Is what you are looking at caused by the time it takes the reference to stabilise?
What is the voltage on the EN pin?

 

Enable voltage is always at 3.2V with and without the capacitor

 

Check the value of your soft start capacitor (SS). The device is behaving as though a long SS has been programmed.