Coreless current sensor bundles advanced fault detection

Allegro MicroSystems, Inc. has introduced the  ACS37610 coreless Hall-effect current sensor for automotive and industrial systems, offering higher accuracy and sensitivity, additional fault detection capabilities, and user programmability. The ACS3761 sensor joins the ACS37612, claiming the industry’s first family of coreless Hall sensing solutions designed to measure currents from 100 A to greater than 4000 A flowing through a busbar or PCB trace with a typical 1 percent accuracy without an external concentrator or U-shaped magnetic shield.

The new features enable higher efficiency and higher power density, while reducing system complexity, bill of materials, cost, footprint, and weight, said Allegro MicroSystems. “Our differential Hall-based sensors provide excellent immunity to stray magnetic fields without the need of a shield, required by competing solutions, that slows down response and adds non-linearity error into the system,” said Shaun Milano, Allegro’s director of current sensors, in a statement.

The ACS37610 can be used in applications such as electric vehicle high-voltage traction motor inverters, 48 V/12 V auxiliary inverters, heterogeneous redundant battery monitoring, overcurrent detection, smart fuses, power distribution units (PDUs), and power supplies.

The sensor’s 250-kHz bandwidth, dedicated overcurrent and overtemperature fault pin, and built-in diagnostics make it suited for safety-critical applications. It also features advanced differential sensing technology, resulting in a 2.5× improvement in signal-to-noise ratio (SNR) and a 2× lower noise relative to the ACS37612. “The lower noise provides superior resolution required for accurate torque control, while the sensor’s 4× higher sensitivity range enables flexible busbar and PCB designs,” said Allegro.

Allegro also noted that a slight notch to the current-carrying busbar or PCB copper trace provides further improvements to the system’s SNR. The ACS37610 features larger Hall element spacing (2.5 mm versus 1.8 mm for the ACS37612) to accommodate wider notches, which results in virtually no thermal performance degradation and no hotspots, according to the company.

The ACS37610 current sensor is available now in a low-profile, lead (Pb)-free, 8-pin surface mount TSSOP package. Allegro offers evaluation kits and reference tools for current flowing through a PCB or busbar.