The ADE78801 is a high accuracy， 3-phase electrical energy measurement IC with serial interfaces and three flexible pulse outputs. The ADE7880 device incorporates second-order sigmadelta （Σ-Δ） analog-to-digital converters （ADCs）， a digital integrator， reference circuitry， and all of the signal processing required to perform the total （fundamental and harmonic） active， and apparent energy measurements， rms calculations， as well as fundamental-only active and reactive energy measurements. In addition， the ADE7880 computes the rms of harmonics on the phase and neutral currents and on the phase voltages， together with the active， reactive and apparent powers， and the power factor and harmonic distortion on each harmonic for all phases. Total harmonic distortion （THD） is computed for all currents and voltages. A fixed function digital signal processor （DSP） executes this signal processing. The DSP program is stored in the internal ROM memory. The ADE7880 is suitable for measuring active， reactive， and apparent energy in various 3-phase configurations， such as wye or delta services with， both， three and four wires. The ADE7880 provides system calibration features for each phase， that is， rms offset correction， phase calibration， and gain calibration. The CF1， CF2， and CF3 logic outputs provide a wide choice of power information： total active powers， apparent powers， or the sum of the current rms values， and fundamental active and reactive powers.