71M6543F Datasheet, PDF (88/157 Pages) Maxim Integrated Products – Selectable Gain of 1 or 8 for One Current Energy Meter ICs Metrology Compensation

71M6543F/H and 71M6543G/GH Data Sheet
4.4 System Using Current Transformers
Figure 32 shows a polyphase system using four current transformers to support optional Neutral current
sensing for anti-tamper purposes. The Neutral current sensing CT can be omitted if Neutral current
sensing is not required. The system is referenced to Neutral (i.e., the Neutral rail is tied to V3P3A and
V3P3SYS).
Current Transformers
A
NEUTRAL
B
C
AMR
IR
HOST
LOAD
Note: This system is referenced to Neutral
POWER SUPPLY
NEUTRAL
MUX and ADC
IADC2
IADC3
}IA
VADC8 (VA)
IADC4 _}IB
IADC5
VADC9 (VB)
IADC6
IADC7
}IC
VADC10 (VC)
IADC0
IADC1
}IN*
V3P3A V3P3SYS GNDA GNDD
TERIDIAN
PWR MODE
CONTROL
71M6543F/ _WAKE-UP
71M6543H/
REGULATOR
71M6543G/
71M6543GH
VBAT
VBAT_RTC
TEMPERATURE ^BATTERY
SENSOR
MONITOR
VREF
SERIAL PORTS
TX
RX
MODUL- _RX
ATOR _TX
POWER FAULT
COMPARATOR
SPI INTERFACE
RAM
COMPUTE
ENGINE
FLASH
MEMORY
MPU
RTC
TIMERS
ICE
COM0...5
SEG
SEG/DIO
LCD DRIVER
DIO, PULSES
DIO
V3P3D
OSCILLATOR/
PLL _XIN
XOUT
*IN = Optional Neutral Current
9/17/2010
BATTERY
RTC
BATTERY
LCD DISPLAY
8888.8888
PULSES,
DIO
I²C or µWire
EEPROM
32 kHz
Figure 32. System Using Current Transformers
88
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