90E21 Datasheet, PDF (3/57 Pages) Integrated Device Technology – Single-Phase High-Performance Wide-Span Energy Metering IC

Table of Contents
FEATURES .............................................................................................................................................................................. 6
APPLICATION ......................................................................................................................................................................... 6
DESCRIPTION......................................................................................................................................................................... 6
BLOCK DIAGRAM .................................................................................................................................................................. 7
1 PIN ASSIGNMENT ............................................................................................................................................................. 9
2 PIN DESCRIPTION .......................................................................................................................................................... 10
3 FUNCTIONAL DESCRIPTION ......................................................................................................................................... 12
3.1 DYNAMIC METERING RANGE .................................................................................................................................................................... 12
3.2 STARTUP AND NO-LOAD POWER ............................................................................................................................................................. 12
3.3 ENERGY REGISTERS .................................................................................................................................................................................. 12
3.4 N LINE METERING AND ANTI-TAMPERING .............................................................................................................................................. 13
3.4.1 Metering Mode and L/N Line Current Sampling Gain Configuration ......................................................................................... 13
3.4.2 Anti-Tampering Mode .................................................................................................................................................................... 13
3.5 MEASUREMENT AND ZERO-CROSSING ................................................................................................................................................... 14
3.5.1 Measurement .................................................................................................................................................................................. 14
3.5.2 Zero-Crossing ................................................................................................................................................................................. 14
3.6 CALIBRATION .............................................................................................................................................................................................. 15
3.7 RESET ........................................................................................................................................................................................................... 15
4 INTERFACE ..................................................................................................................................................................... 16
4.1 SERIAL PERIPHERAL INTERFACE (SPI) ................................................................................................................................................... 16
4.1.1 Four-Wire Mode .............................................................................................................................................................................. 16
4.1.2 Three-Wire Mode ............................................................................................................................................................................ 17
4.1.3 Timeout and Protection ................................................................................................................................................................. 18
4.2 WARNOUT PIN FOR FATAL ERROR WARNING ....................................................................................................................................... 18
4.3 LOW COST IMPLEMENTATION IN ISOLATION WITH MCU ...................................................................................................................... 18
5 REGISTER ........................................................................................................................................................................ 19
5.1 REGISTER LIST ............................................................................................................................................................................................ 19
5.2 STATUS AND SPECIAL REGISTER ............................................................................................................................................................ 21
5.3 METERING/ MEASUREMENT CALIBRATION AND CONFIGURATION .................................................................................................... 25
5.3.1 Metering Calibration and Configuration Register ....................................................................................................................... 25
5.3.2 Measurement Calibration Register ............................................................................................................................................... 32
5.4 ENERGY REGISTER .................................................................................................................................................................................... 37
5.5 MEASUREMENT REGISTER ....................................................................................................................................................................... 41
6 ELECTRICAL SPECIFICATION ....................................................................................................................................... 48
6.1 ELECTRICAL SPECIFICATION ................................................................................................................................................................... 48
6.2 SPI INTERFACE TIMING .............................................................................................................................................................................. 50
6.3 POWER ON RESET TIMING ........................................................................................................................................................................ 51
6.4 ZERO-CROSSING TIMING ........................................................................................................................................................................... 51
6.5 VOLTAGE SAG TIMING ............................................................................................................................................................................... 52
6.6 PULSE OUTPUT ........................................................................................................................................................................................... 52
6.7 ABSOLUTE MAXIMUM RATING .................................................................................................................................................................. 53
PACKAGE DIMENSIONS...................................................................................................................................................... 54
ORDERING INFORMATION.................................................................................................................................................. 57
Table of Contents
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January 10, 2012