Datasheet ADE7753 (Analog Devices)

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Single-Phase Multifunction Metering IC with di/dt Sensor Interface ADE7753 FEATURES
line-voltage period measurement, and rms calculation on the
High accuracy; supports IEC 60687/61036/61268 and
voltage and current. The selectable on-chip digital integrator
IEC 62053-21/62053-22/62053-23
provides direct interface to di/dt current sensors such as
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 Active, reactive, and apparent energy; sampled waveform;
The ADE7753 provides a serial interface to read data, and a
current and voltage rms
pulse output frequency (CF), which is proportional to the active
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 25°C
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 Digital calibration for power, phase, and input offset
The positive-only accumulation mode gives the option to
On-chip temperature sensor (±3°C typical)
accumulate energy only when positive power is detected. An
SPI® compatible serial interface
internal no-load threshold ensures that the part does not exhibit
Pulse output with programmable frequency
any creep when there is no load. The zero-crossing output (ZX)
Interrupt request pin (IRQ) 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. The ADE77531 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 -Δ 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 RESET DVDD DGND INTEGRATOR PGA WGAIN[11:0] ADE7753 MULTIPLIER LPF2 V1P ADC dt 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] x2 PGA VRMSOS[11:0] V2P ADC |x| VADIV[7:0] V2N % % WDIV[7:0] LPF1 ZX 4k SAG 2.4V REGISTERS AND REFERENCE SERIAL INTERFACE
02875-A-001
AGND REF CLKIN CLKOUT DIN DOUT SCLK IN/OUT CS IRQ
Figure 1. 1U.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 license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2003–2010 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS ESD CAUTION TERMINOLOGY PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION ANALOG INPUTS di/dt CURRENT SENSOR AND DIGITAL INTEGRATOR ZERO-CROSSING DETECTION Zero-Crossing Timeout PERIOD MEASUREMENT POWER SUPPLY MONITOR LINE VOLTAGE SAG DETECTION Sag Level Set PEAK DETECTION Peak Level Set Peak Level Record ADE7753 INTERRUPTS Using the ADE7753 Interrupts with an MCU Interrupt Timing TEMPERATURE MEASUREMENT ADE7753 ANALOG-TO-DIGITAL CONVERSION Antialias Filter ADC Transfer Function ADE7753 Reference Circuit CHANNEL 1 ADC Channel 1 Sampling Channel 1 RMS Calculation Channel 1 RMS Offset Compensation CHANNEL 2 ADC Channel 2 Sampling Channel 2 RMS Calculation Channel 2 RMS Offset Compensation PHASE COMPENSATION ACTIVE POWER CALCULATION ENERGY CALCULATION Integration Time under Steady Load POWER OFFSET CALIBRATION ENERGY-TO-FREQUENCY CONVERSION LINE CYCLE ENERGY ACCUMULATION MODE POSITIVE-ONLY ACCUMULATION MODE NO-LOAD THRESHOLD REACTIVE POWER CALCULATION SIGN OF REACTIVE POWER CALCULATION APPARENT POWER CALCULATION Apparent Power Offset Calibration APPARENT ENERGY CALCULATION Integration Times under Steady Load LINE APPARENT ENERGY ACCUMULATION ENERGIES SCALING CALIBRATING AN ENERGY METER BASED ON THE ADE7753 Watt Gain Calibrating Watt Gain Using a Reference Meter Example Calibrating Watt Gain Using an Accurate Source Example Watt Offset Calibrating Watt Offset Using a Reference Meter Example Calibrating Watt Offset with an Accurate Source Example Phase Calibration Calibrating Phase Using a Reference Meter Example Calibrating Phase with an Accurate Source Example VRMS and IRMS Calibration Apparent Energy Reactive Energy CLKIN FREQUENCY SUSPENDING ADE7753 FUNCTIONALITY CHECKSUM REGISTER ADE7753 SERIAL INTERFACE ADE7753 Serial Write Operation ADE7753 Serial Read Operation ADE7753 REGISTERS ADE7753 REGISTER DESCRIPTIONS COMMUNICATIONS REGISTER MODE REGISTER (0x09) INTERRUPT STATUS REGISTER (0x0B), RESET INTERRUPT STATUS REGISTER (0x0C), INTERRUPT ENABLE REGISTER (0x0A) CH1OS REGISTER (0x0D) OUTLINE DIMENSIONS ORDERING GUIDE