ADI’s ADE77531 features proprietary analog to digital converters (ADCs) and digital signal processing (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.

Features and Benefits

• High accuracy; supports IEC 60687/61036/61268 and IEC 62053-21/62053-22/62053-23
• On-chip digital integrator enables direct interface to current sensors with di/dt output
• A PGA in the current channel allows direct interface to shunts and current transformers
• Active, reactive, and apparent energy; sampled waveform; current and voltage rms
• Less than 0.1% error in active energy measurement over a dynamic range of 1000 to 1 at 25°C
• Positive-only energy accumulation mode available
• On-chip user programmable threshold for line voltage surge and SAG and PSU supervisory
• Digital calibration for power, phase, and input offset
• On-chip temperature sensor (±3°C typical)
• Serial peripheral interface (SPI) compatible serial interface
• Pulse output with programmable frequency
• Interrupt request pin (IRQ) and status register