High-Accuracy, Isolated Current Sensor with Stray Field Rejection

The Allegro ACS724/ACS725 family of current sensor ICs are economical and precise solutions for AC or DC current sensing in industrial, automotive, consumer, and communications systems. They are offered in multiple compact packages with a high level of integration that fits various application needs. These devices consist of a precise, low-offset, 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 that is sensed by the integrated Hall IC and converted into a proportional voltage. The current is sensed differentially in order to reject stray fields, improving accuracy in magnetically noisy environments. The current conductor is inherently isolated from the device signal leads due to its internal structure which results in a high isolation voltage rating for the various offered packages. All of these devices offer very low ohmic losses as low as 265 µΩ.

The ACS724/ACS725 devices are provided in small, low-profile surface-mount SOIC8 (LC) and custom SOIC16 packages (MA and MC). The leadframe is plated with 100% matte tin, which is compatible with standard lead (Pb) free printed circuit board assembly processes. 

The MA and LC packages offer high isolation voltage with a maximum nominal current of 50 A, while the MC (20 Mil) package offers up to 90 A nominal current measurement. These current ratings vary depending on the ambient operating temperatures.