ADE7751:  Single Phase Energy Metering IC with On-Chip Fault Detection

The ADE7751 is an accurate fault tolerant electrical energy measurement IC intended for use in two-wire distribution systems. It provides instantaneous and average real power based on line voltage and current. The part specifications surpass the accuracy requirements as quoted in the IEC1036 standard. The only analog circuitry used on the ADE7751 is in the ADCs and reference circuit. All other signal processing (e.g., multiplication and filtering) is carried out in the digital domain. This approach provides superior stability and accuracy over extremes in environmental conditions and over time.

The ADE7751 incorporates a novel fault detection scheme, which both warns of fault conditions and allows the ADE7751 to continue accurate billing during a fault event. The ADE7751 does this by continuously monitoring both the phase and neutral (return) currents. A fault is indicated when these currents differ by more than 12.5%, and billing is continued using the larger of the two currents. Gain calibration between channels is adjusted external to this device. The ADE7751, available in SSOP packages, is pin compatible with the AD7751. It has the same functionalities as the AD7751. The only difference is that its low frequency (F1/F2) and high frequency (CF) outputs are synchronized under all load conditions.