The AD7755 is a high accuracy electrical energy measurement IC. The part specifications surpass the accuracy requirements as quoted in the IEC1036 standard. See Analog Devices' Application Note AN-559 for a description of an IEC1036 watt-hour meter reference design.
The only analog circuitry used in the AD7755 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 AD7755 supplies average real power information on the low frequency outputs F1 and F2. These logic outputs may be used to directly drive an electromechanical counter or interface to an MCU. The CF logic output gives instantaneous real power information. This output is intended to be used for calibration purposes, or interfacing to an MCU.
The AD7755 includes a power supply monitoring circuit on the AVDD supply pin. The AD7755 will remain in a reset condition until the supply voltage on AVDD reaches 4 V. If the supply falls below 4 V, the AD7755 will also be reset and no pulses will be issued on F1, F2 and CF.
Internal phase matching circuitry ensures that the voltage and current channels are phase matched whether the HPF in Channel 1 is on or off. An internal no-load threshold ensures that the AD7755 does not exhibit any creep when there is no load.
The AD7755 is available in 24-lead DIP and SSOP packages.
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High Accuracy, Supports 50 Hz/60 Hz IEC 687/1036 Less than 0.1% Error Over a Dynamic Range of 500 to 1The AD7755 Supplies Average Real Power on the Frequency Outputs F1 and F2The High Frequency Output CF Is Intended for Calibration and Supplies Instantaneous Real PowerThe Logic Output REVP Can Be Used to Indicate a Potential Miswiring or Negative PowerDirect 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 ResistanceProprietary ADCs and DSP Provide High Accuracy over Large Variations in Environmental Conditions and TimeOn-Chip Power Supply MonitoringOn-Chip Creep Protection (No Load Threshold)On-Chip Reference 2.5 V 6 8% (30 ppm/8C Typical) with External Overdrive CapabilitySingle 5 V Supply, Low Power (15 mW Typical)Low Cost CMOS Process
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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
V1P, 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 to +85
Storage Temperature Range . . . . . . . .. . ...... . . 65 to +150
Junction Temperature . . . . . . . . . . . . . ......... . . . .. . . . . . . 150
24-Lead Plastic DIP, Power Dissipation . . . ......... . . . . . 450 mW
JA Thermal Impedance . . . . . . . . . . . . . . ...... . . ... . . 105/W
Lead Temperature, (Soldering 10 sec) . . . . ... .. . . ... . . . 260
24-Lead SSOP, Power Dissipation . . . . . . . . . ........ . . . . 450 mW
JA Thermal Impedance . . . . . . . . . . . . . . . ...... . ... . . 112/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . ...... .. .... . . . . 215
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . ... .. . .... . . . . 220
Post a Buying Lead
Required Field 
