Allegro differential current sensors come in SOIC

April 10, 2016 // By Peter Clarke
Allegro differential current sensor
Hall Effect-based components that operate at 5.0V and 3.3V provide improved current sensing performance in a small package.

Allegro MicroSystems Europe today announced two current sensor ICs suitable for AC or DC current sensing in industrial, commercial, and communication systems but not qualified for automotive applications.

Both the ACS724KMA (5 V) and the ACS725KMA (3.3 V) are available in a SOIC16 wide-body package that provides improved isolation. The differential sensing technology provides immunity to interfering common mode magnetic fields from adjacent current traces or motors. Typical applications include motor control, load detection and management, switched-mode power supplies, and overcurrent fault protection.

Both devices comprise 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 current is sensed differentially in order to reject common-mode fields, improving accuracy in magnetically noisy environments. 

The output of the device has a positive slope when an increasing current flows through the primary copper conduction path (from pins 1 through 4, to pins 5 through 8), which is the path used for current sensing. The internal resistance of this conductive path is 0.85 mΩ typical, providing low power loss.

Related links and articles:

News articles:

Allegro rolls automotive-grade current sensors

DMOS microstepping driver with translator and overcurrent protection

Analog ASIC solves thermal analysis problems