ACS724 and ACS725: 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.

• AEC-Q100 qualified 
• Differential Hall sensing rejects common-mode fields
• 1.2 mΩ primary conductor resistance for low power loss and high inrush current withstand capability
• Integrated shield virtually eliminates capacitive coupling from current conductor to die, greatly suppressing output noise due to high dv/dt transients
• Industry-leading noise performance with greatly improved bandwidth through proprietary amplifier and filter design techniques
• High-bandwidth 120 kHz analog output for faster response times in control applications
• Filter pin allows user to filter the output for improved resolution at lower bandwidth
• Patented integrated digital temperature compensation circuitry allows for near closed-loop accuracy over temperature in an open-loop sensor
• Filter pin simplifies bandwidth limiting for better resolution at lower frequencies
• 5 V, single supply operation

Typical Applications 

• Industrial Motor Control
• DC/DC Converters
• xEV Onboard Chargers (OBC)
• Solar Inverters
• Load Detection and Management
• Switched Mode Power Supplies
• Overcurrent Fault Protection