How susceptible is the ACS714 and ACS715 to stray magnetic fields?
The magnetic coupling of the ACS714 and ACS715 is listed in the datasheets with a nominal value of 12 G/A. What this means is, for every ampere of current, 12 G of field is produced at the Hall element. For stray fields, the effect on the device can be calculated by dividing 12 G/A by the mV/A sensitivity of the device in use. This allows you to predict the Gauss per millivolt change at the output. The susceptibility of the ACS714 and ACS715 to external fields can be mitigated via proper orientation, spacing from external field sources, and if necessary, shielding of the device. An application note, Managing External Magnetic Field Interference When Using ACS70x and ACS71x Current Sensor ICs addresses mitigation techniques in greater detail. It can be downloaded from: http://www.allegromicro.com/techpub2/an/an26030.pdf.
