TPS54160: Load regulation and line regulation

Part Number: TPS54160

Hi,

What is the cause of load regulation and line regulation? 

I can see a slightly Vout drop, for example, set Vout 3.3V, but test Vout 3.28V. Firstly i thought it is the probe resistance between Vout test point and electronic load.

When i google it, find out it's also related to control loop. Maybe the EA? i'm not sure about it, so i need your help.

Or you can send me some learning resources to my e-mail: mason-liu@ti.com.

Thanks.

Best regards

Mason Liu