AD7751

a FEATURES High Accuracy, Supports 50 Hz/60 Hz IEC 687/1036 Less than 0.1% Error Over a Dynamic Range of 500 to 1 Supplies Average Real Power on the Frequency Outputs F1 and F2 High-Frequency Output CF Is Intended for Calibration and Supplies Instantaneous Real Power Continuous Monitoring of the Phase and Neutral Current Allows Fault Detection in Two-Wire Distribution Systems AD7751 Uses the Larger of the Two Currents (Phase or Neutral) to Bill—Even During a Fault Condition Two Logic Outputs (FAULT and REVP) Can be Used to Indicate a Potential Miswiring or Fault Condition Direct Drive for Electromechanical Counters and Two-Phase Stepper Motors (F1 and F2) A PGA in the Current Channel Allows the Use of Small Values of Shunt and Burden Resistance Proprietary ADCs and DSP Provide High Accuracy Over Large Variations in Environmental Conditions and Time On-Chip Power Supply Monitoring On-Chip Creep Protection (No Load Threshold) On-Chip Reference 2.5 V ؎ 8% (30 ppm/؇ C Typical) with External Overdrive Capability Single 5 V Supply, Low Power (15 mW Typical) Low-Cost CMOS Process GENERAL DESCRIPTION Energy Metering IC With On-Chip Fault Detection AD7751* The only analog circuitry used in the AD7751 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 AD7751 incorporates a novel fau...