Digital-output current sensor monitors power with precision

March 05, 2014 // By Graham Prophet
The ACS764 from Allegro MicroSystems Europe is a low-noise precision digital current sensor IC targeted at server, telecom, and power monitoring IC applications at up to 100V within the industrial, consumer and computer markets.

The integrated Hall-effect current sensor IC is Allegro’s first digital current sensor IC , 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, 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 16A and 32A (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 comes in a 24-pin QSOP package (suffix LF).

Allegro MicroSystems;