90E32 Datasheet, PDF (3/71 Pages) Integrated Device Technology – Poly-Phase High-Performance Wide-Span Energy Metering IC

Table of Contents
FEATURES .............................................................................................................................................................................. 7
APPLICATION ......................................................................................................................................................................... 7
GENERAL DESCRIPTION ...................................................................................................................................................... 7
BLOCK DIAGRAM .................................................................................................................................................................. 8
1 PIN ASSIGNMENT ............................................................................................................................................................. 9
2 PIN DESCRIPTION .......................................................................................................................................................... 10
3 FUNCTION DESCRIPTION .............................................................................................................................................. 12
3.1 POWER SUPPLY .......................................................................................................................................................................................... 12
3.2 CLOCK .......................................................................................................................................................................................................... 12
3.3 RESET ........................................................................................................................................................................................................... 12
3.3.1 RESET Pin ....................................................................................................................................................................................... 12
3.3.2 Power On Reset (POR) .................................................................................................................................................................. 12
3.3.3 Software Reset ............................................................................................................................................................................... 12
3.4 METERING FUNCTION ................................................................................................................................................................................ 13
3.4.1 Theory of Energy Registers .......................................................................................................................................................... 13
3.4.2 Energy Registers ............................................................................................................................................................................ 15
3.4.3 Energy Pulse Output ...................................................................................................................................................................... 15
3.4.4 Startup and No-load Power ........................................................................................................................................................... 15
3.5 MEASUREMENT FUNCTION ....................................................................................................................................................................... 17
3.5.1 Active/ Reactive/ Apparent Power ................................................................................................................................................ 17
3.5.2 Fundamental / Harmonic Active Power ........................................................................................................................................ 17
3.5.3 Mean Power Factor (PF) ................................................................................................................................................................ 17
3.5.4 Voltage / Current RMS ................................................................................................................................................................... 17
3.5.5 Phase Angle .................................................................................................................................................................................... 18
3.5.6 Frequency ....................................................................................................................................................................................... 18
3.5.7 Temperature ................................................................................................................................................................................... 18
3.5.8 THD+N for Voltage and Current .................................................................................................................................................... 18
3.6 POWER MODE .............................................................................................................................................................................................. 19
3.6.1 Normal Mode (N Mode) .................................................................................................................................................................. 19
3.6.2 Idle Mode (I Mode) .......................................................................................................................................................................... 20
3.6.3 Detection Mode (D Mode) .............................................................................................................................................................. 22
3.6.4 Partial Measurement mode (M Mode) ........................................................................................................................................... 23
3.6.5 Transition of Power Modes ........................................................................................................................................................... 24
3.7 EVENT DETECTION ..................................................................................................................................................................................... 25
3.7.1 Zero-Crossing Detection ............................................................................................................................................................... 25
3.7.2 Sag Detection ................................................................................................................................................................................. 25
3.7.3 Phase Loss Detection .................................................................................................................................................................... 25
3.7.4 Computed Neutral Line Overcurrent Detection ........................................................................................................................... 25
3.7.5 Phase Sequence Error Detection ................................................................................................................................................. 25
3.8 DC AND CURRENT RMS ESTIMATION ...................................................................................................................................................... 25
4 SPI INTERFACE ............................................................................................................................................................... 26
4.1 INTERFACE DESCRIPTION ......................................................................................................................................................................... 26
4.2 SPI INTERFACE ............................................................................................................................................................................................ 27
4.2.1 SPI Slave Interface Format ............................................................................................................................................................ 27
4.2.2 Reliability Enhancement Feature .................................................................................................................................................. 27
5 CALIBRATION METHOD ................................................................................................................................................. 28
5.1 NORMAL MODE OPERATION CALIBRATION ........................................................................................................................................... 28
Table of Contents
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December 9, 2011