The ADE7854 / ADE7858 / ADE7868 / ADE7878 are high accuracy, 3-phase electrical energy measurement ICs with serial interfaces and three flexible pulse outputs. The ADE78xx devices incorporate second-order sigma-delta (Σ-∆) analog-to-digital converters (ADCs), a digital integrator, reference circuitry, and all of the signal processing required to perform total (fundamental and harmonic) active, reactive (ADE7878, ADE7868, and ADE7858), and apparent energy measurement and rms calculations, as well as fundamental-only active and reactive energy measurement (ADE7878) and rms calculations. A fixed function digital signal processor (DSP) executes this signal processing. The DSP program is stored in the internal ROM memory.
The ADE7854 / ADE7858 / ADE7868 / ADE7878 are 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 ADE78xx devices provide 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, reactive, and apparent powers, or the sum of the current rms values, and fundamental active and reactive powers.
The ADE7854 / ADE7858 / ADE7868 / ADE7878 contain waveform sample registers that allow access to all ADC outputs. The devices also incorporate power quality measurements, such as short duration low or high voltage detections, short duration high current variations, line voltage period measurement, and angles between phase voltages and currents. Two serial interfaces, SPI and I2C, can be used to communicate with the ADE78xx. A dedicated high speed interface, the high speed data capture (HSDC) port, can be used in conjunction with I2C to provide access to the ADC outputs and real-time power information. The ADE7854 / ADE7858 / ADE7868 / ADE7878 also have two interrupt request pins, IRQ0 and IRQ1, to indicate that an enabled interrupt event has occurred. For the ADE7868 / ADE7878, three specially designed low power modes ensure the continuity of energy accumulation when the ADE6878 / ADE7878 is in a tampering situation. See Table 1 for a quick reference chart listing each part and its functions. The ADE78xx are available in the 40-lead LFCSP, Pb-free package.
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