The Allegro ACS726 current sensor IC family provides
economical and precise solutions for AC current sensing in
industrial, commercial, and communications systems. The
device package allows for easy implementation by the customer.
Typical applications include motor control, load detection and
management, switched-mode power supplies, and overcurrent
fault protection.
The fully differential output gives superior immunity to output
offset drift as well common mode noise.
ACS726 is the first current sensor IC to include a fully
differential back-end amplifier (BEA) that can be used to adjust
gain and bandwidth via external RC networks. The BEA is
fully independent and when unused, it can be powered down
to reduce power consumption.
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. Device accuracy is optimized 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 differential
voltage (VOUTP – VOUTN) when an increasing current flows through
the primary copper conduction path (from pins 1 through 6, to pins
7 through 12), which is the path used for current sensing. The internal
resistance of this conductive path is 1.1 mΩ typical, providing low
power loss.
The terminals of the conductive path are electrically isolated from
the sensor IC signal leads (pins 13 through 24). This allows the
ACS726 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 ACS726 is provided in a small, low-profile surface mount
QSOP24 package (suffix LF). The leadframe is plated with 100%
matte tin, which is compatible with standard lead (Pb) free printed
circuit board assembly processes. Internally, the device is Pb-free,
except for flip-chip high-temperature Pb-based solder balls, currently
exempt from RoHS. The device, excluding the BEA, is fully calibrated
prior to shipment from the factory.
