71M6521DE Datasheet, PDF (6/107 Pages) Teridian Semiconductor Corporation – Energy Meter IC

71M6521DE/DH/FE Data Sheet
List of Figures
Figure 1: IC Functional Block Diagram....................................................................................................................................9
Figure 2: General Topology of a Chopped Amplifier .............................................................................................................11
Figure 3: AFE Block Diagram.................................................................................................................................................13
Figure 4: Samples from Multiplexer Cycle ............................................................................................................................16
Figure 5: Accumulation Interval ............................................................................................................................................16
Figure 6: Interrupt Structure .................................................................................................................................................37
Figure 7: Optical Interface....................................................................................................................................................40
Figure 8: Connecting an External Load to DIO Pins ..............................................................................................................42
Figure 9: 3-Wire Interface. Write Command, HiZ=0..............................................................................................................44
Figure 10: 3-Wire Interface. Write Command, HiZ=1............................................................................................................44
Figure 11: 3-Wire Interface. Read Command........................................................................................................................45
Figure 12: 3-Wire Interface. Write Command when CNT=0..................................................................................................45
Figure 13: 3-Wire Interface. Write Command when HiZ=1 and WFR=1. ..............................................................................45
Figure 14: Functions defined by V1 ......................................................................................................................................46
Figure 15: Voltage. Current, Momentary and Accumulated Energy ......................................................................................48
Figure 16: Timing Relationship between ADC MUX, Compute Engine, and Serial Transfers................................................49
Figure 17: RTM Output Format .............................................................................................................................................49
Figure 18: Operation Modes State Diagram..........................................................................................................................52
Figure 19: Functional Blocks in BROWNOUT Mode (inactive blocks grayed out).................................................................53
Figure 20: Functional Blocks in LCD Mode (inactive blocks grayed out)..............................................................................54
Figure 21: Functional Blocks in SLEEP Mode (inactive blocks grayed out) ..........................................................................55
Figure 22: Transition from BROWNOUT to MISSION Mode when System Power Returns..................................................56
Figure 23: Power-Up Timing with V3P3SYS and VBAT tied together...................................................................................56
Figure 24: Power-Up Timing with VBAT only .......................................................................................................................57
Figure 25: Wake Up Timing...................................................................................................................................................58
Figure 26: MPU/CE Data Flow...............................................................................................................................................59
Figure 27: MPU/CE Communication .....................................................................................................................................59
Figure 28: Resistive Voltage Divider (Left), Current Transformer (Right) ............................................................................60
Figure 29: Resistive Shunt ....................................................................................................................................................60
Figure 30: Error Band for VREF over Temperature (Regular-Accuracy Parts)......................................................................62
Figure 31: Error Band for VREF over Temperature (High-Accuracy Parts)...........................................................................63
Figure 32: Crystal Frequency over Temperature ...................................................................................................................64
Figure 33: Crystal Compensation..........................................................................................................................................65
Figure 34: Connecting LCDs .................................................................................................................................................66
Figure 35: I²C EEPROM Connection......................................................................................................................................68
Figure 36: Three-Wire EEPROM Connection.........................................................................................................................69
Figure 37: Connections for the RX Pin..................................................................................................................................69
Figure 38: Connection for Optical Components ....................................................................................................................70
Figure 39: Voltage Divider for V1..........................................................................................................................................70
Figure 40: External Components for RESET: Development Circuit (Left), Production Circuit (Right) ..................................71
Figure 41: External Components for the Emulator Interface.................................................................................................71
Figure 42: Wh Accuracy, 0.1A to 200A at 240V/50Hz and Room Temperature....................................................................97
Figure 43: Meter Accuracy over Harmonics at 240V, 30A ....................................................................................................97
Figure 44: Typical Meter Accuracy over Temperature Relative to 25°C (71M6521FE).........................................................98
Page: 6 of 107
Rev 2