ATT7022CU

The ATT7022 is a high-precision three-phase energy metering IC designed for three-phase three-wire and three-phase four-wire applications. It integrates six second-order sigma-delta ADCs, a voltage reference circuit, and DSP circuitry for all power, energy, RMS, power factor, and frequency measurements. It measures per-phase and combined active power, reactive power, apparent power, active energy, and reactive energy, while also measuring per-phase current and voltage RMS values, power factor, phase angle, frequency, and other parameters — fully meeting the requirements of three-phase multi-rate multifunctional energy meters. It supports all-digital gain and phase correction, i.e., pure software meter calibration. The active and reactive energy pulse outputs CF1 and CF2 provide instantaneous active and reactive power information, which can be connected directly to a reference meter for error calibration. An SPI interface is provided for convenient transfer of metering parameters and calibration parameters between the device and an external MCU. The internal voltage monitoring circuit ensures normal operation during power-up and power-down events.

Key features

• Active measurement: Class 0.5S/0.2S, compliant with IEC 687/1036, GB/T 17883-1999
• Reactive measurement: Class 2/Class 3, compliant with IEC 1268, GB/T 17882-1999
• Supports 3-phase 3-wire and 3-phase 4-wire configurations
• Instantaneous active, reactive, and apparent power measurement; active and reactive energy measurement
• Power factor, phase, frequency, RMS voltage and current measurement
• Per-phase and combined-phase parameters provided simultaneously
• Phase sequence detection and phase loss detection
• Selectable combined-phase energy accumulation mode (algebraic sum / absolute value sum)
• RMS value of the vector sum of three-phase currents in 3-phase 4-wire mode
• Direct active and reactive meter calibration pulse output
• Adjustable meter constant
• Adjustable startup current
• Forward and reverse active energy data
• Reverse active energy indication
• Four-quadrant reactive parameters
• Software meter calibration with gain and phase compensation, small-current nonlinearity compensation
• Active and reactive power measurement up to the 21st harmonic and above
• SPI interface for easy communication with external MCU
• Single +5V supply
• QFP44 package