Allegro has developed a range of high-current automotive-grade current sensors in packages only 1.5mm thick.

The Hall sensors are differential to reject common-mode fields  – from nearby current-carrying conductors, for example.

The devices consist of a precision low-offset linear Hall circuit with a copper conduction path located near the die (see photo).

Applied current generates a magnetic field which the Hall IC converts into a proportional voltage.

Sensitivity and zero-current output voltage is factory programmed.

Errors are cut by a chopper-stabilized signal path and digital temperature compensation, and proprietary internal shielding increases immunity to dV/dt in the sense wire and and stray electric fields – important for high-side high-voltage applications. Isolation is up to 100V.

The internal resistance of the oxygen-free copper conductive path is typically 200μΩ, and its thickness provides some over-load protection.

Automotive applications include electric power steering, dc-dc converters, oil pumps and air-con pumps.

Allegro also sees the sensor in industrial applications such as motor drives, plus in computer servers and telecom inverters.

ACS780 are 4.5 to 5.5V parts and ACS781 are 3 to 3.6V.

Table transcription not guaranteed, ACS780 parts are similar