Current sensor IC combines low noise, high precision and digital output

The new fully integrated Hall-effect current sensor IC is the first digital current sensor IC released by Allegro, and is designed for applications that require digital current sensing and reporting through an I²C™ bus. Factory programming of the offset and gain, including the temperature coefficients, stabilises 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. An integrated low-resistance conductor means that external shunt resistors are not required and, by employing Hall-effect sensing technology, eliminates the error normally associated with the sensor resistance varying with temperature. The device allows 16 unique I²C™ bus addresses, selectable via external pins. A digital synchronisation input pin also provides the ability to obtain multiple sensor readings with the same time stamp. The device is highly configurable and includes an averaging filter that is user controlled. Full-scale current-sensing ranges of 16 A and 32 A (unidirectional sensing) are available as standard options. The device also incorporates a digital over-current fault output and internal averaging filter, both of which are user configurable through the I²C™ bus. The ACS764XLFTR-T is provided in a compact 24-pin QSOP package (suffix LF). The leadframe is plated with 100% matt tin, which is compatible with standard lead (Pb) free printed circuit board assembly processes. Internally, the device is lead-free, except for flip-chip high-temperature lead-based solder balls, currently exempt from RoHS.