New Low Noise, High Precision Digital Output Current Sensor IC

Mar12_AllegroAllegro MicroSystems, LLC has introduced the first digital current sensor IC targeted at server, telecom and power monitoring current sensor IC applications within the industrial, consumer and computer markets. Allegro’s 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 percent over the operating temperature range. 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 ACS764 sensor IC full scale 16 A and 32 A unidirectional sensing are 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. A digital synchronization input pin also provides the ability to obtain multiple sensor readings with the same time stamp.

The ACS764XLFTR-T is provided in a compact 24-pin QSOP package (suffix LF). The leadframe is plated with 100 percent 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. It is priced at $1.60 in quantities of 1,000.