71m6511h-igtr Maxim Integrated Products, Inc., 71m6511h-igtr Datasheet - Page 80

• Manufacturer Part Number: 71m6511h-igtr
• Description: Single-phase Energy Meter Ic
• Manufacturer: Maxim Integrated Products, Inc.

I2C EEPROMs or other I2C compatible devices should be connected to the DIO pins DIO4 and DIO5, as shown in Figure 35.
Pull-up resistors of roughly 3kΩ to V3P3 should be used for both SCL and SDA signals. The DIO_EEX register in I/O RAM
must be set to 1 in order to convert the DIO pins DIO4 and DIO5 to I2C pins SCL and SDA.
In general, all pins of the 71M6511 are compatible with external 5V devices. The exceptions are the power supply pins and the
RX pin of the UART (see section Electrical Specifications).
Figure 36 shows how a 5V signal from an external device can be safely interfaced to the RX pin.
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R1 = 100kΩ
V
IN
© 2005-2007 TERIDIAN Semiconductor Corporation
V3P3
Figure 36: Interfacing RX to a 0-5V Signal
71M6511
71M6511
Figure 35: EEPROM Connection
Connecting I2C EEPROMs
Connecting 5V Devices
DIO4
DIO4
DIO5
DIO5
RX
3kΩ
3kΩ
Single-Phase Energy Meter IC
71M651X
3kΩ
3kΩ
EEPROM
EEPROM
SCL
SCL
SDA
SDA
V3P3
V3P3
71M6511/71M6511H
DATA SHEET
AUGUST 2007
V2.6