TPS48111Q1EVM: Recommended current sensing method

Part Number: TPS48111Q1EVM

Tool/software:

Hi,

For TPS48111, is it recommended to sense current using the MOSFET’s RDS(on) (lossless sensing) or by using an external shunt resistor with the VSNS/IMON pins?

What are the main pros and cons of each method in terms of accuracy, thermal drift, and power loss?

Regards,

Michelle Mathew

  • Hi Michelle, 

    Firstly the TPS4811 does not support VDS sensing. Only high side sensing via shunt resistor. There is a copy paste error in this datasheet that we are working to resolve. Please reference TPS1211 which has the same feature descriptions at TPS4811 just different operating voltages. 

    Secondly, the shunt resistor is a more accurate method for sensing as its characteristics are not expected to change over time with heat the way VDS sensing does. 

    Thanks, 

    Sarah