General Description
The MAXQ3181 is a dedicated electricity measurement front-end that collects and calculates polyphase voltage, current, active power and energy, and many other metering parameters of a polyphase load. The computed results can be retrieved by an external master through the on-chip serial peripheral interface (SPI™) bus. This bus is also used by the external master to configure the operation of the MAXQ3181 and monitor the status of operations.

Features
♦ Compatible with 3-Phase/3-Wire, 3-Phase/4-Wire, and Other 3-Phase Services
♦ 0.1% Active Power and Energy Linearity Error
♦ 0.5% Apparent Power and Energy Linearity Error
♦ 0.5% Linearity Errors for RMS Voltage and RMS Current
♦ Neutral Line Current Measurement
♦ Line Frequency (Hz)
♦ Power Factors
♦ Phase Sequence Indication
♦ Phase Voltage Absence Detection
♦ Programmable Pulse Width
♦ Programmable No-Load Current Threshold
♦ Programmable Meter Constant
♦ Programmable Thresholds for Undervoltage and Overvoltage Detection
♦ Programmable Threshold for Overcurrent Detection
♦ Amp-Hours in Absence of Voltage Signals
♦ On-Chip Digital Temperature Sensor
♦ Precision Internal Voltage Reference 2.048V (30ppm/°C typical), Also Supports An External Voltage Reference
♦ Active Power and Energy of Each Phase and Combined 3-Phase (kWh), Positive and Negative
♦ Apparent Power and Energy of Each Phase and Combined 3-Phase
♦ Supports Software Meter Calibration
♦ Up to 3-Point Multipoint Calibration to Compensate for Transducer Nonlinearity
♦ Power-Fail Detection
♦ Bidirectional Reset Input/Output
♦ SPI-Compatible Serial Interface with Interrupt Request (IRQ) Output
♦ Single 3.3V Supply, Low Power (35mW typical)

Applications
    3-Phase Active Energy Electricity Meters