LM25119: Can shunt resistor replaced by the bottom mosfet RDSon like LM25116

Hello,

A regular resistor was always used. Not sure with NMOS Rds/on.

Regards 

Mahmoud,

What is the major different on current sensing perspective between Rshunt and Mosfet Rds(on)?

Can LM25119 support such replacement?

Bests

Using FET Rds/on, there is few 100pF parasitic capacitance in parallel to the On resistance. The impedance is Ron/(1 + Cp*Ron*S). The time constant is Cp*Ron and it is very small. By theory should be similar to a shunt resistor.

Regards

Mahmoud,

1) May I ask what does "S" stand for?

2) Okay then the only missing puzzle is that the CS pin is able to handle such switching voltage range.

I might be wrong but the  Absolute Maximum Ratings CS1, CS2 is only 0.3V.

So if voltage divider is used to split the switching node to a point that is within such range is this still valid to do so?

Bests

the "S" is Laplace variable.

that is right the abs max on CS1 and CS2 is only 0.3V.

Regards