MP2908A DCR current sensing

DC-DC Power Converters
#1

Hello,

I have a question about the MP2908A controller.

Is it possible to use DCR current sensing instead of a shunt resistor ?
I am concerned about the quite high CS pins input currents.

If it is possible, do you have specific circuit recommandation or guidelines ?
If not, do you have other parts that can do it ?

Thanks.

#2

Wow you are careful! Internet rando, here. Impossible to say the issue is the current mismatch between the two inputs and that isn’t clear at all. Add to that that the bias current is specified as a typical and there is no min or max could be ± 1A for all we know.

#3

I do not say there is an issue, I just want to know if it is possible or has been done.

I read somewhere that CS amplifier inputs should be high impedance for this sensing method. If not that may cause DC bias on the sensed current.

Indeed the datasheet gives little informations on the CS pins impedance and does not mention DCR CS as other manufacturers do and that raised my concerns …