Datasheet ATM90E26 (Microchip) - 10

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3 FUNCTIONAL DESCRIPTION 3.1 DYNAMIC METERING RANGE
Accuracy is 0.1% for active energy metering and 0.2% for reactive energy metering over a dynamic range of 5000:1 (typi- cal). Refer to Table-2 and Table-3.
Table-2 Active Energy Metering Error Current Power Factor Error
(%) 20mA ≤ I ＜ 50mA ±0.2 1.0 50mA ≤ I ≤ 100A ±0.1 50mA ≤ I ＜ 100mA 0.5 (Inductive) ±0.2 100mA ≤ I ≤ 100A 0.8 (Capacitive) ±0.1 Note: Shunt resistor is 250 μΩ or CT ratio is 1000:1 and load resistor is 6Ω.
Table-3 Reactive Energy Metering Error Current sin
φ
(Inductive or Capacitive) Error
(
%
) 20mA ≤ I ＜ 50mA ±0.4 1.0 50mA ≤ I ≤ 100A ±0.2 50mA ≤ I ＜ 100mA ±0.4 0.5 100mA ≤ I ≤ 100A ±0.2 Note: Shunt resistor is 250 μΩ or CT ratio is 1000:1 and load resistor is 6Ω.
3.2 STARTUP AND NO-LOAD POWER
Startup and no-load power thresholds are programmable, both for active and reactive power. The related registers are listed in Table-4.
Table-4 Threshold Configuration for Startup and No-Load Power Threshold Register
Threshold for Active Startup Power PStartTh, 27H Threshold for Active No-load Power PNolTh, 28H Threshold for Reactive Startup Power QStartTh, 29H Threshold for Reactive No-load Power QNolTh, 2AH The M90E26 will start within 1.2 times of the theoretical startup time of the configured startup power, if startup power is less than the corresponding power of 20mA when power factor or sinφ is 1.0. The M90E26 has no-load status bits, the Pnoload/Qnoload bit (EnStatus, 46H). The M90E26 will not output any active pulse (CF1) in active no-load state. The M90E26 will not output any reactive pulse (CF2) in reactive no-load state. M90E26 [DATASHEET] 10 Atmel-46002B-SE-M90E26-Datasheet_110714 Document Outline Features Application Description Block Diagram 1 Pin Assignment 2 Pin Description 3 Functional Description 3.1 Dynamic Metering Range 3.2 Startup and No-Load Power 3.3 Energy Registers 3.4 N Line Metering and Anti-Tampering 3.4.1 Metering Mode and L/N Line Current Sampling Gain Configuration 3.4.2 Anti-Tampering Mode Threshold Compare Method Special Treatment at Low Power 3.5 Measurement and Zero-Crossing 3.5.1 Measurement 3.5.2 Zero-Crossing 3.6 Calibration 3.7 Reset 4 Interface 4.1 SPI Interface 4.1.1 Four-Wire Mode Read Sequence Write Sequence 4.1.2 Three-Wire Mode 4.1.3 Timeout and Protection 4.2 UART Interface 4.2.1 Byte Level Timing 4.2.2 Write Transaction 4.2.3 Read transaction 4.2.4 Checksum 4.3 WarnOut Pin for Fatal Error Warning 4.4 Low Cost Implementation in Isolation with MCU 5 Register 5.1 Register List 5.2 Status and Special Register SoftReset Software Reset SysStatus System Status FuncEn Function Enable SagTh Voltage Sag Threshold SmallPMod Small-Power Mode LastData Last Read/Write SPI/UART Value 5.3 Metering/ Measurement Calibration and Configuration 5.3.1 Metering Calibration and Configuration Register LSB RMS/Power 16-bit LSB CalStart Calibration Start Command PLconstH High Word of PL_Constant PLconstL Low Word of PL_Constant Lgain L Line Calibration Gain Lphi L Line Calibration Angle Ngain N Line Calibration Gain Nphi N Line Calibration Angle PStartTh Active Startup Power Threshold PNolTh Active No-Load Power Threshold QStartTh Reactive Startup Power Threshold QNolTh Reactive No-Load Power Threshold MMode Metering Mode Configuration CS1 Checksum 1 5.3.2 Measurement Calibration Register AdjStart Measurement Calibration Start Command Ugain Voltage rms Gain IgainL L Line Current rms Gain IgainN N Line Current rms Gain Uoffset Voltage Offset IoffsetL L Line Current Offset IoffsetN N Line Current Offset PoffsetL L Line Active Power Offset QoffsetL L Line Reactive Power Offset PoffsetN N Line Active Power Offset QoffsetN N Line Reactive Power Offset CS2 Checksum 2 5.4 Energy Register Theory of Energy Registers APenergy Forward Active Energy ANenergy Reverse Active Energy ATenergy Absolute Active Energy RPenergy Forward (Inductive) Reactive Energy RNenergy Reverse (Capacitive) Reactive Energy RTenergy Absolute Reactive Energy EnStatus Metering Status 5.5 Measurement Register Irms L Line Current rms Urms Voltage rms Pmean L Line Mean Active Power Qmean L Line Mean Reactive Power Freq Voltage Frequency PowerF L Line Power Factor Pangle Phase Angle between Voltage and L Line Current Smean L Line Mean Apparent Power Irms2 N Line Current rms Pmean2 N Line Mean Active Power Qmean2 N Line Mean Reactive Power PowerF2 N Line Power Factor Pangle2 Phase Angle between Voltage and N Line Current Smean2 N Line Mean Apparent Power 6 Electrical Specification 6.1 Electrical Specification 6.2 SPI Interface Timing 6.3 Power On Reset Timing 6.4 Zero-Crossing Timing 6.5 Voltage Sag Timing 6.6 Pulse Output 6.7 Absolute Maximum Rating Ordering Information Packaging Drawings Revision History