ACS764: Fully Integrated, Hall-Effect Based Current Sensor IC With I²C Digital Output and Low-Resistance Current Conductor

The Allegro™ ACS764 fully integrated Hall-effect current sensor IC is designed for applications that require digital current sensing and reporting through an I²C™ bus. Allegro factory programming of the offset and gain, including the temperature coefficients, stabilizes the offset and gain over the operating temperature range. This programming greatly reduces the device total error, typically less than 2% over the operating temperature range. A fast response digital fault output is also provided. Both coarse sensitivity and fault level can be programmed via an I²C control register, and can be used for enhanced diagnostic functions.

The integrated low resistance conductor eliminates the requirement for external shunt resistors and, by employing Hall-effect sensing technology, eliminates the error associated with changing sense resistance due to temperature. The device allows 16 unique I²C bus addresses, selectable via external pins. The sensor IC gain can be selected by the user through the I²C bus. The device uses a BiCMOS process that allows a highly stable chopper-stabilized small signal amplifier design.

The ACS764 is provided in a compact 24-pin QSOP 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.

This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: December 5, 2016

Recommended Substitutions: no direct replacement. For existing customer transition, and for new customers or new applications, contact Allegro Sales

• Fully integrated current sensor IC in a compact QSOP package eliminates the need for shunt resistors
• Hall effect sensing technology eliminates the error associated with shunt resistor variation due to temperature
• High accuracy: typical error <2% over operating temperature range
• Fast response digital fault output with programmable level through I²C bus interface
• Digital output through I²C interface with 9-bit A-to-D conversion for high resolution current measurement
• User-selectable decimation averaging of current output; up to 256 samples
• Freeze pin for holding current measurement value while reading many sensors serially
• User-selectable (via I²C) coarse sensitivity and OC fault levels, for exceptional flexibility to meet application requirements
• Less than 0.5 mΩ series resistance greatly reduces power dissipation and heat generation
• Factory programmed temperature compensation stabilizes sensitivity and offset voltage throughout the operating temperature range
• 16 programmable I²C addresses
• Unidirectional DC current sensing and reporting
• Immunity to stray magnetic fields simplifies PCB layout