The ACS711 from Allegro MicroSystems Europe is a Hall-effect linear current sensor IC with a built-in over-current fault output that provides AC or DC current sensing in audio, communications, white goods, and automotive applications operating at voltages up to 100V. The device 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. The output has a positive slope proportional to the current flow from the positive to the negative input pins. The internal resistance of this path is typically 1.2mΩ, providing a non-intrusive measurement interface that saves power. The low-noise analogue signal path has a bandwidth of 100kHz. The device offers ±12.5 and ±25A full-scale sensing ranges, and is designed for 3.3 to 5.5V single-supply operation. No external sense resistor is required. The over-current active-low fault output trips and latches at 100% full-scale current. The thickness of the copper conductor allows device survival at up to five times the specified over-current condition, claims the company. The device is housed in a small, surface mount SOIC8 package.