71M6541D Datasheet, PDF (94/166 Pages) Maxim Integrated Products – 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs

71M6541D/F/G and 71M6542F/G Data Sheet
4.4 71M6541D/F/G Using 71M6x01and Current Shunts
Figure 36 shows a typical connection for one isolated and one non-isolated shunt sensor, using the
71M6x01 Isolated Sensor Interface. This configuration implements a single-phase measurement with
tamper-detection using the second current sensor. This configuration can also be used to create a split
phase meter (e.g., ANSI Form 2S). For best performance, the IAP-IAN current sensor input is configured
for differential mode (i.e., DIFFA_E = 1, I/O RAM 0x210C[4]). The outputs of the 71M6x01 Isolated Sensor
Interface are routed through a pulse transformer, which is connected to the pins IBP-IBN. The IBP-IBN
pins must be configured for remote sensor communication (i.e., RMT_E =1, I/O RAM 0x2709[3]). See
Figure 3 for the AFE configuration corresponding to Figure 36.
Shunt
NEUTRAL
LINE
Shunt
LOAD
Note:
This system is referenced to LINE
NEUTRAL
LINE
POWER SUPPLY
TERIDIAN
71M6xx1
Pulse
Trans-
former
AMR
IR
HOST
MUX and ADC V3P3A V3P3SYS _{GNDA GNDD}
IAP
PWR MODE
IAN
CONTROL
TERIDIAN ^WAKE-UP
71M6541D/F REGULATOR
VBAT
VA
VBAT_RTC
IBP
TEMPERATURE ^BATTERY
IBN
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
11/5/2010
Figure 36: 71M6541D/F/G with 71M6x01 isolated Sensor
BATTERY
RTC
BATTERY
LCD DISPLAY
8888.8888
PULSES,
DIO
I²C or µWire
EEPROM
32 kHz