The AMR sensor has an internal clock signal. AMR sensor sensing the external magnetic field is carried out according to the internal clock.
The clock frequency is referred to as response frequency. AMR sensors with high response frequencies can be used to detect faster movements such as meter rotations, but they consume larger currents. The lower the response frequency, the lower the current consumption, but such AMR sensors are used to sense relatively infrequent movements such as those of notebook PC lids.
The combination of low consumption current with high response frequency is available in the AMRUS74S and AMRUS74X