Described as the first surface-mount current sensors with a reinforced isolation rating, the ACS717 and ACS718 consist of a low-offset, linear Hall sensor circuit with a copper conduction path located near the surface of the die. Current flowing through the copper conduction path generates a magnetic field that is sensed by the integrated Hall IC and converted into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic field to the Hall transducer. A proportional voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed for accuracy after packaging. 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. Price for either device is $1.87 each/1,000.
Datasheet are available:
• ACS717: http://www.allegromicro.com/en/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs/ACS717.aspx
• ACS718: http://www.allegromicro.com/en/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs/ACS718.aspx