solved

 

AFAICR it is a very low resistor in the gnd connection of the FETs into the sense pin.
fraction of an ohm is required
Max.

 

The value of the current-sense resistor is chosen such that it drops 100mV when the motor current is the limit value you want. For example, to limit the current to 1A the resistor value would be 100mV/1A = 100mΩ.