Thermally-Enhanced, Hall-Effect-Based High-Precision Linear Current Sensor ICOctober 28, 2013 by Jeff Shepard
Allegro MicroSystems, LLC announced a new thermally-enhanced, fully-integrated, hall-effect-based, high precision linear current sensor IC to their existing portfolio. Allegroâ€™s ACS770 device consists of a precision, low-offset linear Hall circuit with a copper conduction path located near the die. Applied current flowing through this copper conduction path generates a magnetic field which the Hall IC converts into a proportional voltage. This new device is targeted at the automotive, industrial and renewable energy markets.
Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer. A precise, proportional output voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed and calibrated for accuracy at the factory. Proprietary digital temperature compensation technology greatly improves the ICâ€™s accuracy and temperature stability without influencing the high-bandwidth operation of the analog output.
High level immunity to the current conductor dV/dt and stray electric fields, offered by Allegro proprietary integrated shield technology for low output voltage ripple and low offset drift in high-side, high voltage applications. The output of the device has a positive slope (>VCC / 2) when an increasing current flows through the primary copper conduction path (from terminal 4 to terminal 5), which is the path used for current sampling. The internal resistance of this conductive path is 100 Î¼Î© typical, providing low power loss. The thickness of the copper conductor allows survival of the device at high overcurrent conditions.
The terminals of the conductive path are electrically isolated from the signal leads (pins 1 through 3). This allows the ACS770 family of sensor ICs to be used in applications requiring electrical isolation without the use of optoisolators or other costly isolation techniques. The ACS770 family is lead (Pb) free. All leads are plated with 100% matte tin, and there is no lead inside the package. The heavy gauge lead frame is made of oxygen-free copper. The ACS770 is available in a 5-pin package (suffix CB). Pricing for 1,000 pieces is $3.32 each.