Single-Phase Multifunction Metering IC with di/dt Sensor Interface ADE7753 line-voltage period measurement, and rms calculation on the FEATURES voltage and current. The selectable on-chip digital integrator High accuracy supports IEC 60687/61036/61268 and provides direct interface to di/dt current sensors such as IEC 62053-21/62053-22/62053-23 On-chip digital integrator enables direct interface to current Rogowski coils, eliminating the need for an external analog sensors with di/dt output integrator and resulting in excellent long-term stability and pre- A PGA in the current channel allows direct interface to cise phase matching between the current and voltage channels. shunts and current transformers The ADE7753 provides a serial interface to read data, and a Active, reactive, and apparent energy sampled waveform pulse output frequency (CF), which is proportional to the active current and voltage rms Less than 0.1% error in active energy measurement over a power. Various system calibration features, i.e., channel offset dynamic range of 1000 to 1 at 25C correction, phase calibration, and power calibration, ensure Positive-only energy accumulation mode available high accuracy. The part also detects short duration low or high On-chip user programmable threshold for line voltage surge voltage variations. and SAG and PSU supervisory The positive-only accumulation mode gives the option to Digital calibration for power, phase, and input offset accumulate energy only when positive power is detected. An On-chip temperature sensor (3C typical) internal no-load threshold ensures that the part does not exhibit SPI compatible serial interface Pulse output with programmable frequency any creep when there is no load. The zero-crossing output (ZX) IRQ Interrupt request pin ( ) and status register produces a pulse that is synchronized to the zero-crossing point Reference 2.4 V with external overdrive capability of the line voltage. This signal is used internally in the line cycle Single 5 V supply, low power (25 mW typical) active and apparent energy accumulation modes, which enables GENERAL DESCRIPTION faster calibration. 1 The ADE7753 features proprietary ADCs and DSP for high The interrupt status register indicates the nature of the interrupt, accuracy over large variations in environmental conditions and and the interrupt enable register controls which event produces time. The ADE7753 incorporates two second-order 16-bit - an output on the IRQ pin, an open-drain, active low logic output. ADCs, a digital integrator (on CH1), reference circuitry, The ADE7753 is available in a 20-lead SSOP package. temperature sensor, and all the signal processing required to perform active, reactive, and apparent energy measurements, FUNCTIONAL BLOCK DIAGRAM AVDD DVDD DGND RESET INTEGRATOR WGAIN 11:0 PGA ADE7753 MULTIPLIER LPF2 V1P dt ADC V1N HPF1 CFNUM 11:0 TEMP APOS 15:0 SENSOR PHCAL 5:0 2 DFC CF IRMSOS 11:0 CFDEN 11:0 VAGAIN 11:0 2 x PGA VRMSOS 11:0 V2P ADC x % % VADIV 7:0 WDIV 7:0 V2N LPF1 ZX SAG 4k 2.4V REGISTERS AND SERIAL INTERFACE REFERENCE 02875-A-001 AGND REF CLKIN CLKOUT DIN DOUT SCLK CS IRQ IN/OUT Figure 1. 1 U.S. Patents 5,745,323 5,760,617 5,862,069 5,872,469. Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20032010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. ADE7753 TABLE OF CONTENTS Features .............................................................................................. 1 Energy Calculation ..................................................................... 29 General Description ......................................................................... 1 Power Offset Calibration ........................................................... 31 Functional Block Diagram .............................................................. 1 Energy-to-Frequency Conversion............................................ 31 Revision History ............................................................................... 3 Line Cycle Energy Accumulation Mode ................................. 33 Specif icat ions ..................................................................................... 4 Positive-Only Accumulation Mode ......................................... 33 Timing Characteristics ..................................................................... 6 No-Load Threshold .................................................................... 33 Absolute Maximum Ratings ............................................................ 7 Reactive Power Calculation ...................................................... 33 ESD Caution .................................................................................. 7 Sign of Reactive Power Calculation ......................................... 35 Terminology ...................................................................................... 8 Apparent Power Calculation ..................................................... 35 Pin Configuration and Function Descriptions ............................. 9 Apparent Energy Calculation ................................................... 36 Typical Performance Characteristics ........................................... 11 Line Apparent Energy Accumulation ...................................... 37 Theory of Operation ...................................................................... 16 Energies Scaling .......................................................................... 38 Analog Inputs .............................................................................. 16 Calibrating an Energy Meter Based on the ADE7753 ........... 38 di/dt Current Sensor and Digital Integrator ............................... 17 CLKIN Frequency ...................................................................... 48 Zero-Crossing Detection ........................................................... 18 Suspending ADE7753 Functionality ....................................... 48 Period Measurement .................................................................. 19 Checksum Register..................................................................... 48 Power Supply Monitor ............................................................... 19 ADE7753 Serial Interface .......................................................... 49 Line Voltage Sag Detection ....................................................... 19 ADE7753 Registers ......................................................................... 52 Peak Detection ............................................................................ 20 ADE7753 Register Descriptions ................................................... 55 ADE7753 Interrupts ................................................................... 21 Communications Register ......................................................... 55 Temperature Measurement ....................................................... 22 Mode Register (0x09) ................................................................. 55 ADE7753 Analog-to-Digital Conversion ................................ 22 Interrupt Status Register (0x0B), Reset Interrupt Status Register (0x0C), Interrupt Enable Register (0x0A) .............. 57 Channel 1 ADC .......................................................................... 23 CH1OS Register (0x0D) ............................................................ 58 Channel 2 ADC .......................................................................... 25 Outline Dimensions ....................................................................... 59 Phase Compensation .................................................................. 27 Ordering Guide .......................................................................... 59 Active Power Calculation .......................................................... 28 Rev. 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