TPS548B28pwwr

Hello Anne, 

What you highlighted in you SCH above need to be connected ground connection of the remote sensing signal. The recommended VSNS– operating range  as referred to AGND pin to be within  is –50 mV to +50 mV. 

Here is our recommendation for remote sense connections:

1. Connected the FB voltage divider resistors to the remote location, this will allow sensing to the output voltage at a remote location.
2. The connections from the FB voltage divider resistors to the remote location must be a pair of PCB traces with at least 12-mil trace width,
3. Implement Kelvin sensing across a high bypass capacitor of 0.1 μF or higher.
4. The ground connection of the remote sensing signal must be connected to the VSNS– pin.
5. The VOUT connection of the remote sensing signal must be connected to the feedback resistor divider with the lower feedback resistor, and should be terminated at VSNS– pin.

Please use Webench to create an initial design based on your conditions 

https://www.ti.com/product/TPS548B28

Thanks! 

Tahar

Hi Tahar: 

Thanks for your answear , I want to know further that if the VSNS- should be connected to AND or PGND?