Analog Devices

The ADE7752B is a high accuracy polyphase electrical energy measurement IC. The ADE7752B specifications surpass the accuracy requirements as quoted in the IEC62053-21 standard. The only analog circuitry used in the ADE7752B is in the analog-to-digital converters (ADCs) and reference circuit. All other signal processing (for example, multiplication, filtering, and summation) is carried out in the digital domain. This approach provides superior stability and accuracy over extremes in environmental conditions and over time.The ADE7752B supplies average active power information on the low frequency outputs, F1 and F2. These logic outputs can be used to directly drive an electromechanical counter or to interface with a microcontroller (MCU). The CF logic output gives instantaneous active power information. This output is intended to be used for calibration purposes.The ADE7752B includes a power supply monitoring circuit on the VDDpin. The ADE7752B remains inactive until the supply voltage on VDDreaches 4 V. If the supply falls below 4 V, the ADE7752B resets and no pulses are issued on F1, F2, and CF.Internal phase matching circuitry ensures that the voltage and current channels are phase matched. An internal no load threshold ensures that the ADE7752B does not exhibit any creep when there is no load.The ADE7752B is available in a 24-lead SOIC package.

The ADE7753 features proprietary ADCs and DSP for high accuracy over large variations in environmental conditions and time. The ADE7753 incorporates two second-order 16-bit Σ-Δ ADCs, a digital integrator (on CH1), reference circuitry, temperature sensor, and all the signal processing required to perform active, reactive, and apparent energy measurements, line-voltage period measurement, and rms calculation on the voltage and current. The selectable on-chip digital integrator provides direct interface to di/dt current sensors such as Rogowski coils, eliminating the need for an external analog integrator and resulting in excellent long-term stability and precise phase matching between the current and voltage channels.The ADE7753 provides a serial interface to read data, and a pulse output frequency (CF), which is proportional to the active power. Various system calibration features, i.e., channel offset correction, phase calibration, and power calibration, ensure high accuracy. The part also detects short duration low or high voltage variations.The positive-only accumulation mode gives the option to accumulate energy only when positive power is detected. An internal no-load threshold ensures that the part does not exhibit any creep when there is no load. The zero-crossing output (ZX) produces a pulse that is synchronized to the zero-crossing point of the line voltage. This signal is used internally in the line cycle active and apparent energy accumulation modes, which enables faster calibration.The interrupt status register indicates the nature of the interrupt, and the interrupt enable register controls which event produces an output on theIRQpin, an open-drain, active low logic output. The ADE7753 is available in a 20-lead SSOP package.NOTE: For polyphase system designs, theADE7758is recommended.

The ADE7757 is an accurate electrical energy measurement integrated circuit. It is a pin reduction version of ADE7755 with an enhancement of a precise oscillator circuit that serves as a clock source to the chip. The ADE7757 eliminates the cost of an external crystal or resonator, thus reducing the overall cost of a meter built with this IC. The chip directly interfaces with shunt resistor.The ADE7757 provides instantaneous and average real power based on line current and voltage. The part specifications surpass the accuracy requirements as quoted in the IEC61036 standard. The only analog circuitry used in the ADE7757 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 small analog input full-scale allows the chip to interface to low value shunt resistances without losing dynamic range. The ADE7757 is available in 16-lead SOIC narrow-body package.The Application NoteAN-679can be used as a basis for a description of an IEC61036 low cost, watt-hour meter reference design.NOTE: For polyphase system designs, theADE7752Ais recommended.

The ADE7757A (AD71056) is an accurate electrical energy measurement integrated circuit. It is a pin reduction version of ADE7755 with an enhancement of a precise oscillator circuit that serves as a clock source to the chip. The ADE7757A eliminates the cost of an external crystal or resonator, thus reducing the overall cost of a meter built with this IC. The chip directly interfaces with shunt resistor.The ADE7757A provides instantaneous and average real power based on line current and voltage. The part specifications surpass the accuracy requirements as quoted in the IEC61036 standard. The only analog circuitry used in the ADE7757A 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 small analog input full-scale allows the chip to interface to low value shunt resistances without losing dynamic range. The ADE7757A is available in 16-lead SOIC narrow-body package.TheApplication Note AN-679can be used as a basis for a description of an IEC62053-21 low cost, watt-hour meter reference design.NOTE: For polyphase system designs, theADE7752Ais recommended.

The ADE7758 is a high accuracy, 3-phase electrical energy measurement IC with a serial interface and two pulse outputs. The ADE7758 incorporates second-order Σ-Δ ADCs, a digital integrator, reference circuitry, a temperature sensor, and all the signal processing required to perform active, reactive, and apparent energy measurement and rms calculations.The ADE7758 is suitable to measure active, reactive, and apparent energy in various 3-phase configurations, such as WYE or DELTA services, with both three and four wires. The ADE7758 provides system calibration features for each phase, that is, rms offset correction, phase calibration, and power calibration. The APCF logic output gives active power information, and the VARCF logic output provides instantaneous reactive or apparent power information.The ADE7758 has a waveform sample register that allows access to the ADC outputs. The part also incorporates a detection circuit for short duration low or high voltage variations. The voltage threshold levels and the duration (number of half-line cycles) of the variation are user programmable. A zero-crossing detection is synchronized with the zero-crossing point of the line voltage of any of the three phases. This information can be used to measure the period of any one of the three voltage inputs. The zero-crossing detection is used inside the chip for the line cycle energy accumulation mode. This mode permits faster and more accurate calibration by synchronizing the energy accumulation with an integer number of line cycles.Data is read from the ADE7758 via the SPI serial interface. The interrupt request output (IRQ) is an open-drain, active low logic output. TheIRQoutput goes active low when one or more interrupt events have occurred in the ADE7758. A status register indicates the nature of the interrupt. The ADE7758 is available in a 24-lead SOIC package.

The ADE7759 is an accurate active power and energy measurement IC with a serial interface and a pulse output. The ADE7759 incorporates two second-order sigma-delta ADCs, a digital integrator (on CH1), reference circuitry, temperature sensor and all the signal processing required to perform active power and energy measurement.An on-chip digital integrator provides direct interface to current sensors such as Rogowski coil, which have di/dt output. The digital integrator eliminates the need for external analog integrator, and this solution provides excellent long-term stability and precise phase matching between the current and voltage channels. The integrator can be switched on and off based on the current sensor selected.The ADE7759 is available in 20-lead SSOP package, and it is pin-to-pin compatible with theADE7753and ADE7756.NOTE: If your application requires the measurement of rms voltage and current, theADE7763is recommended.