The ACS711 consists of a linear Hall sensor circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field, which is sensed by the integrated Hall IC and converted into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer. Full-scale sensing options within the ACS711 family include ±12.5 and ±25A.
The output of the device has a positive slope proportional to the current flow from IP+ to IP– (pins 1 and 2, to pins 3 and 4). The internal resistance of this conductive path is 1.2mΩ typical, providing a non-intrusive measurement interface that saves power in applications that require energy efficiency.
The ACS711 is optimised for low-side current sensing applications, although the terminals of the conductive path are electrically isolated from the sensor leads (pins 5 through 8), providing sufficient internal creepage and clearance dimensions for low AC or DC working voltage applications. The thickness of the copper conductor allows survival of the device at up to five times over-current conditions. The ACS711 is provided in a single small-form-factor surface-mount SOIC8 package, and obviating the need for an external sense resistor.
The low-voltage ACS711 family complements Allegro’s existing range of high-voltage products covering 0–200A. Samples of the ACS711 family are now available from Solid State Supplies.