71M6543F Datasheet, PDF (94/157 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
behavior of each individual part across industrial temperatures (see 4.5.3 Temperature Coefficients for
the 71M6543H). The resulting tracking of the reference VREF voltage is within ±10 ppm/°C.
4.6 Connecting I²C EEPROMs
I²C EEPROMs or other I²C compatible devices should be connected to the DIO pins SEGDIO2 and
SEGDIO3, as shown in Figure 33.
Pullup resistors of roughly 10 kΩ to V3P3D (to ensure operation in BRN mode) should be used for both
SDCK and SDATA signals. The DIO_EEX (I/O RAM 0x2456[7:6]) field must be set to 01 in order to convert
the DIO pins SEGDIO2 and SEGDIO3 to I²C pins SCL and SDATA.
10 kΩ
V3P3D
10 kΩ
DIO2
DIO3
EEPROM
SDCK
SDATA
71M6543
Figure 33: I²C EEPROM Connection
4.7 Connecting Three-Wire EEPROMs
µWire EEPROMs and other compatible devices should be connected to the DIO pins SEGDIO2 and
SEGDIO3, as described in 2.5.11 EEPROM Interface on page 66.
4.8 UART0 (TX/RX)
The UART0 RX pin should be pulled down by a 10 kΩ resistor and additionally protected by a 100 pF
ceramic capacitor, as shown in Figure 34.
71M6543
RX
100 pF 10 kΩ
RX
TX
TX
Figure 34: Connections for UART0
4.9 Optical Interface (UART1)
The OPT_TX and OPT_RX pins can be used for a regular serial interface (by connecting a RS_232
transceiver for example), or they can be used to directly operate optical components (for example, an
infrared diode and phototransistor implementing a FLAG interface). Figure 35 shows the basic connections
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