The device and method monitor the current delivered to a load through a power transistor including a sense transistor. The circuit includes a disturbances attenuating circuit that has a differential stage, and first, second and third stages referenced to ground, the respective input nodes of which are connected in common to an output node of the differential stage. The third stage is formed by a transistor identical to a transistor of the first stage and delivers a current signal through a current terminal thereof, proportional to the current being delivered to the load.