Datasheet

ADE7854/ADE7858/ADE7868/ADE7878 Data Sheet
Rev. G | Page 2 of 100
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 3
Functional Block Diagrams ............................................................. 5
Specifications ..................................................................................... 9
Timing Characteristics .............................................................. 12
Absolute Maximum Ratings .......................................................... 15
Thermal Resistance .................................................................... 15
ESD Caution ................................................................................ 15
Pin Configuration and Function Descriptions ........................... 16
Typical Performance Characteristics ........................................... 18
Test Circuit ...................................................................................... 21
Terminology .................................................................................... 22
Power Management ........................................................................ 23
PSM0—Normal Power Mode (All Parts) ................................ 23
PSM1—Reduced Power Mode (ADE7868, ADE7878 Only) 23
PSM2—Low Power Mode (ADE7868, ADE7878 Only) ....... 23
PSM3—Sleep Mode (All Parts) ................................................ 24
Power-Up Procedure .................................................................. 26
Hardware Reset ........................................................................... 27
Software Reset Functionality .................................................... 27
Theory of Operation ...................................................................... 28
Analog Inputs .............................................................................. 28
Analog-to-Digital Conversion .................................................. 28
Current Channel ADC............................................................... 29
di/dt Current Sensor and Digital Integrator .............................. 31
Voltage Channel ADC ............................................................... 32
Changing Phase Voltage Datapath ........................................... 33
Power Quality Measurements ................................................... 34
Phase Compensation ................................................................. 39
Reference Circuit ........................................................................ 41
Digital Signal Processor ............................................................. 42
Root Mean Square Measurement ............................................. 43
Active Power Calculation .......................................................... 47
Reactive Power Calculation—ADE7858, ADE7868, ADE7878
Only .............................................................................................. 52
Apparent Power Calculation ..................................................... 57
Waveform Sampling Mode ....................................................... 60
Energy-to-Frequency Conversion............................................ 60
No Load Condition .................................................................... 64
Checksum Register..................................................................... 65
Interrupts ..................................................................................... 66
Serial Interfaces .......................................................................... 68
Quick Setup as Energy Meter ................................................... 75
Layout Guidelines....................................................................... 75
Crystal Circuit ............................................................................ 76
ADE7878 Evaluation Board ...................................................... 76
Die Version .................................................................................. 76
Silicon Anomaly ............................................................................. 77
ADE7854/ADE7858/ADE7868/ADE7878 Functionality
Issues ............................................................................................ 77
Functionality Issues .................................................................... 77
Section 1. ADE7854/ADE7858/ADE7868/ADE7878
Functionality Issues .................................................................... 79
Registers List ................................................................................... 80
Outline Dimensions ....................................................................... 98
Ordering Guide .......................................................................... 98