ACS724
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package
FEATURES AND BENEFITS
• AEC-Q100 qualified
DESCRIPTION
TheAllegro™ ACS724 current sensor IC is an economical and
precise solution for AC or DC current sensing in industrial,
automotive, commercial, and communications systems. The
small package is ideal for space-constrained applications
while also saving costs due to reduced board area. Typical
applications include motor control, load detection and
management, switched-mode power supplies, and overcurrent
fault protection.
• 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
The device consists 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 which is sensed
by the integrated Hall IC and converted into a proportional
voltage. The current is sensed differentially in order to reject
common-mode fields, improving accuracy in magnetically
noisyenvironments.Theinherentdeviceaccuracyisoptimized
through the close proximity of the magnetic field to the Hall
transducer. A precise, 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 and
2, to pins 3 and 4), which is the path used for current sensing.
Theinternalresistanceofthisconductivepathis1.2mΩtypical,
providing low power loss.
• Patented integrated digital temperature compensation
circuitry allows for near closed loop accuracy over
temperature in an open loop sensor
• Small-footprint, low-profile SOIC8 package suitable for
space-constrained applications
• Filter pin simplifies bandwidth limiting for better
resolution at lower frequencies
Continued on the next page…
Package: 8-Pin SOIC (suffix LC)
TÜV America
Certificate Number:
U8V 14 11 54214 032
The terminals of the conductive path are electrically isolated
from the sensor leads (pins 5 through 8). This allows the
ACS724currentsensorICtobeusedinhigh-sidecurrentsense
applicationswithouttheuseofhigh-sidedifferentialamplifiers
or other costly isolation techniques.
CB 14 11 54214 031
CB Certificate Number:
US-22334-A2-UL
Not to scale
Continued on the next page…
1
8
VCC
IP+
IP+
+IP
The ACS724 outputs an
analog signal, VIOUT , that
changes proportionally
with the bidirectional AC
ACS724
7
6
2
VIOUT
IP
or DC primary sensed
current, IP, within the
specified measurement
CBYPASS
0.1 µF
3
4
FILTER
GND
IP–
IP–
range. The FILTER pin
–IP
CLOAD
can be used to decrease
the bandwidth in order
to optimize the noise
performance.
CF
1 nF
5
Typical Application
ACS724-DS, Rev. 8
MCO-0000227
January 23, 2018