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)Pinout
Specifications(TA = 25°C unless otherwise noted)
AVDD to AGND . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to +7 V
DVDD to DGND . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to +7 V
DVDD to AVDD . . . . . . . . . . . . . . . . . . . . . . 0.3 V to +0.3 V
Analog Input Voltage to AGND
V1A, V1B, V1N, V2P, and V2N . . . . . . . . . . 6 V to +6 V
Reference Input Voltage to AGND . . 0.3 V to AVDD + 0.3 V
Digital Input Voltage to DGND . . . . 0.3 V to DVDD + 0.3 V
Digital Output Voltage to DGND . . . 0.3 V to DVDD + 0.3 V
Operating Temperature Range
Industrial (A, B Versions) . . . . . . . . . . . . . 40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . 65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
24-Lead Plastic DIP, Power Dissipation . . . . . . . . . . 450 mW
JA Thermal Impedance . . . . . . . . . . . . . . . . . . . . 105°C/W
Lead Temperature, (Soldering 10 sec) . . . . . . . . . . . 260°C
24-Lead SSOP, Power Dissipation . . . . . . . . . . . . . . 450 mW
JA Thermal Impedance . . . . . . . . . . . . . . . . . . . . 112°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
DescriptionThe AD7751 is a high-accuracy fault-tolerant electrical energy measurement IC that is intended for use with 2-wire distribution systems. The part specifications surpass the accuracy requirements as quoted in the IEC1036 standard.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 fault detection scheme that warns of fault conditions and allows the AD7751 to continue accurate billing during a fault event. The AD7751 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%. Billing is continued using the larger of the two currents.
AD7751* Data Sheet
