Datasheet ADE7978, ADE7933, ADE7932, ADE7923 (Analog Devices) - 5

Data Sheet ADE7978/ADE7933/ADE7932/ADE7923 GENERAL DESCRIPTION
The ADE7978, the ADE7933/ADE7932, and ADE7923 form a The ADE7933/ADE7932 are available in a 20-lead, Pb-free, wide- chipset dedicated to measuring 3-phase electrical energy using body SOIC package with increased creepage. The ADE7923 is shunts as current sensors. available in a similar 20-lead, Pb-free, wide-body SOIC package The ADE7933/ADE7932 are isolated, 3-channel sigma-delta without the increased creepage. analog-to-digital converters (Σ-Δ ADCs) for polyphase energy The ADE7978 is a high accuracy, 3-phase electrical energy metering applications that use shunt current sensors. The measurement IC with serial interfaces and three flexible pulse ADE7923 is a nonisolated, 3-channel Σ-Δ ADC for the neutral line outputs. The ADE7978 can interface with up to four ADE7933/ that uses a shunt current sensor. The ADE7932 features two ADCs, ADE7932 and ADE7923 devices. The ADE7978 incorporates all and the ADE7933 and ADE7923 feature three ADCs. the signal processing required to perform total (fundamental and One channel is dedicated to measuring the voltage across the harmonic) active, reactive, and apparent energy measurement shunt when a shunt is used for current sensing. This channel and rms calculations, as well as fundamental-only active and provides a signal-to-noise ratio (SNR) of 67 dB over a 3.3 kHz reactive energy measurement and rms calculations. A fixed signal bandwidth. Up to two additional channels are dedicated function digital signal processor (DSP) executes this signal to measuring voltages, which are usually sensed using resistor processing. dividers. The ADE7978 measures the active, reactive, and apparent energy The unused voltage channels on the neutral ADE7923 can be in various 3-phase configurations, such as wye or delta services, used for auxiliary voltage measurements. These channels provide with both three and four wires. The ADE7978 provides system an SNR of 75 dB over a 3.3 kHz signal bandwidth. One voltage calibration features for each phase, gain calibration, and optional channel can be used to measure the temperature of the die via offset correction. Phase compensation is also available, but it is an internal sensor. not necessary because the currents are sensed using shunts. The CF1, CF2, and CF3 logic outputs provide a wide selection of The ADE7933 and ADE7923 include three channels: one power information: total active, reactive, and apparent powers; current channel and two voltage channels. The ADE7932 the sum of the current rms values; and fundamental active and includes one current channel and one voltage channel, but is reactive powers. otherwise identical to the ADE7933. The ADE7978 incorporates power quality measurements, such The ADE7933/ADE7932 include isoPower®, an integrated, as short duration low or high voltage detection, short duration isolated dc-to-dc converter. Based on the Analog Devices, Inc., high current variations, line voltage period measurement, and iCoupler® technology, the dc-to-dc converter provides the angles between phase voltages and currents. Two serial interfaces, regulated power required by the first stage of the ADCs at a SPI and I2C, can be used to communicate with the ADE7978. 3.3 V input supply. The ADE7933/ADE7932 eliminate the need A dedicated high speed interface—the high speed data capture for an external dc-to-dc isolation block. The iCoupler chip scale (HSDC) port—can be used in conjunction with I2C to provide transformer technology is used to isolate the logic signals access to the ADC outputs and real-time power information. between the first and second stages of the ADC. The result is a The ADE7978 also has two interrupt request pins, IRQ0 and small form factor, total isolation solution. The ADE7923 is the IRQ1, to indicate that an enabled interrupt event has occurred. nonisolated version of the ADE7933 that can be used for neutral current measurement when isolation from the neutral The ADE7978 is available in a 28-lead, Pb-free LFCSP package. line is not required. Note that throughout this data sheet, multifunction pins, such The ADE7933/ADE7932 and ADE7923 contain a digital interface as SCLK/SCL, are referred to by the entire pin name or by a that is specially designed to interface with the ADE7978. Using single function of the pin, for example, SCLK, when only that this interface, the ADE7978 accesses the ADC outputs and function is relevant. configuration settings of the ADE7933/ADE7932 and ADE7923. Rev. D | Page 5 of 125 Document Outline Features Applications Typical Application Circuit Revision History General Description Functional Block Diagrams Specifications System Specifications, ADE7978 and ADE7933/ADE7932/ADE7923 ADE7978 Specifications I2C Interface Timing Parameters SPI Interface Timing Parameters HSDC Interface Timing Parameters ADE7933/ADE7932 Specifications Regulatory Approvals Insulation and Safety Related Specifications DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 Insulation Characteristics ADE7923 Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configurations and Function Descriptions Typical Performance Characteristics Total Energy Linearity over Supply and Temperature Fundamental Energy and RMS Linearity with Fifth Harmonic over Supply and Temperature Total Energy Error over Frequency RMS Linearity over Temperature and RMS Error over Frequency Energy Linearity Repeatability Cumulative Histograms of ADC Gain Temperature Coefficients Test Circuit Terminology Theory of Operation ADE7933/ADE7932/ADE7923 Analog Inputs Analog-to-Digital Conversion Oversampling Noise Shaping Antialiasing Filter ADC Transfer Function Untitled Current Channel ADC Current Waveform Gain Registers Current Channel HPF Current Channel Sampling Voltage Channel ADCs Second Voltage Channel and Temperature Measurement Voltage Waveform Gain Registers Voltage Channel HPF Voltage Channel Sampling Changing the Phase Voltage Datapath Reference Circuits Phase Compensation Digital Signal Processor Power Quality Measurements Zero-Crossing Detection Zero-Crossing Timeout Phase Sequence Detection Time Interval Between Phases Period Measurement Phase Voltage Sag Detection Sag Detection Level Setting Peak Detection Overvoltage and Overcurrent Detection Overvoltage Detection Overcurrent Detection Overvoltage and Overcurrent Level Setting Neutral Current Mismatch Root Mean Square Measurement Current RMS Calculation Current RMS Offset Compensation Voltage RMS Calculation Voltage RMS Offset Compensation Voltage RMS in Delta Configurations Active Power Calculation Total Active Power Calculation Fundamental Active Power Calculation Active Power Gain Calibration Active Power Offset Calibration Sign of Active Power Calculation Active Energy Calculation Integration Time Under Steady Load Energy Accumulation Modes BWATTHR and BFWATTHR Accumulation Register in 3-Phase, 3-Wire Configurations Line Cycle Active Energy Accumulation Mode Reactive Power Calculation Total Reactive Power Calculation Fundamental Reactive Power Calculation Reactive Power Gain Calibration Reactive Power Offset Calibration Sign of Reactive Power Calculation Reactive Energy Calculation Integration Time Under Steady Load Energy Accumulation Modes BWATTHR and BFWATTHR Accumulation Register in 3-Phase, 3-Wire Configurations Line Cycle Reactive Energy Accumulation Mode Apparent Power Calculation Apparent Power Gain Calibration Apparent Power Offset Calibration Apparent Power Calculation Using VNOM Apparent Energy Calculation Integration Time Under Steady Load Energy Accumulation Mode BWATTHR and BFWATTHR Accumulation Register in 3-Phase, 3-Wire Configurations Line Cycle Apparent Energy Accumulation Mode Power Factor Calculation and Total Harmonic Distortion Calculation Power Factor Calculation Total Harmonic Distortion Calculation Waveform Sampling Mode Energy-to-Frequency Conversion TERMSELx[2:0] Bits CFxSEL[2:0] Bits Energy-to-Frequency Conversion Process Synchronizing Energy Registers with the CFx Outputs Energy Registers and CFx Outputs for Various Accumulation Modes Sign of Sum of Phase Powers in the CFx Datapath No Load Condition No Load Detection Based on Total Active and Reactive Powers No Load Detection Based on Fundamental Active and Reactive Powers No Load Detection Based on Apparent Power Interrupts Using the Interrupts with an MCU Power Management DC-to-DC Converter Magnetic Field Immunity Power-Up Procedure Initializing the Chipset Hardware Reset ADE7978/ADE7933/ADE7932 and ADE7923 Chipset Software Reset ADE7933/ADE7932 and ADE7923 Software Reset Low Power Mode Applications Information Differences Between the ADE7923 and the ADE7933/ADE7932 ADE7978, ADE7933/ADE7932 and ADE7923 in Polyphase Energy Meters ADE7978 Quick Setup as an Energy Meter Bit Stream Communication Between the ADE7978 and the ADE7933/ADE7932 and ADE7923 ADE7978, ADE7933/ADE7932, and ADE7923 Clocks Insulation Lifetime Layout Guidelines ADE7978 and ADE7933/ADE7932 Evaluation Board ADE7978 Die Version Serial Interfaces Serial Interface Selection Communication Verification I2C-Compatible Interface I2C Write Operation I2C Read Operation I2C Burst Read Operation SPI-Compatible Interface SPI Write Operation SPI Read Operation SPI Burst Read Operation HSDC Interface Checksum Register Register List Outline Dimensions Ordering Guide