The Allegro ACS718 current sensor IC is an economical, high
isolation solution for AC or DC current sensing in industrial,
commercial, and communications systems. The small package is
ideal for space-constrained applications, though the wide-body
provides the creepage and clearance needed for high isolation.
Typical applications include motor control, load detection and
management, switched-mode power supplies, and overcurrent
fault protection.
The device consists of a 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 which 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, providing low power loss.
The terminals of the conductive path are electrically isolated
from the sensor leads (pins 10 through 15 ). This allows the
ACS718 current sensor IC to be used in high-side current sense
applications without the use of high-side differential amplifiers
or other costly isolation techniques.
The ACS718 is provided in a small, low profile surface mount
SOICW16 package (suffix MA). The device is lead (Pb) free
with 100% matte tin leadframe plating. The device is fully
calibrated prior to shipment from the factory.
