71M6601-IL Datasheet, PDF (9/19 Pages) Maxim Integrated Products – Isolated Sensor ICs

Shunt Current Sensors
C
NEUTRAL
B
A
LOAD
71M6xxx Data Sheet
POWER SUPPLY
NEUTRAL
Note: This system is referenced to Neutral
3x 71M6xx3
Pulse Transformers
AMR
IR
HOST
MUX and ADC
IADC0
IADC1
}IN*
VADC10 (VC)
IADC6
IADC7
}IC
VADC9 (VB)
IADC4
IADC5
}IB
VADC8 (VA)
IADC2
IADC3
}IA
V3P3A V3P3SYS GNDA GNDD
71M6543F/
71M6543H
PWR MODE
CONTROL
WAKE-UP
REGULATOR
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 = Neutral Current
9/17/2010
BATTERY
RTC
BATTERY
LCD DISPLAY
8888.8888
PULSES,
DIO
I²C or µWire
EEPROM
32 kHz
Figure 4: Current Sensors Connected to the 71M6543F/H or 71M6545/H with Three 71M6xx3
3.4 PCB Layout Considerations
To limit emissions and susceptibility to electromagnetic and magnetic fields, the signal wiring between the
shunt resistors and the 71M6xxx should be as short as possible and should consist of tightly twisted pair
cable. Similarly, the PCB traces between the 71M6xxx and the 71M654x should be routed as short as
possible and should be surrounded by grounded copper structures. The trace pairs should be routed as
close to each other as permitted by the PCB manufacturer.
The copper separation (gap) between the shunt side and the 71M654x side of the signal transformer
should be as wide as permitted by the footprint of the transformer, as shown in Figure 5.
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