Datasheet

71M6511/71M6511H
Single-Phase Energy Meter IC
DATA SHEET
NOVEMBER 2010
Page: 82 of 98 © 2005–2010 Teridian Semiconductor Corporation V2.7
A Maxim Integrated Products Brand
Connecting I2C EEPROMs
I2C EEPROMs or other I2C compatible devices should be connected to the DIO pins DIO4 and DIO5, as shown in Figure 33.
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.
DIO4
DIO5
71M6511
EEPROM
SCL
SDA
V3P3
3kΩ
3kΩ
DIO4
DIO5
71M6511
EEPROM
SCL
SDA
V3P3
3kΩ
3kΩ
Figure 33: EEPROM Connection
Connecting 5V Devices
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).
71M651X
V
IN
RX
R1 = 100kΩ
V3P3
Figure 34: Interfacing RX to a 0-5V Signal
Figure 34 shows how a 5V signal from an external device can be safely interfaced to the RX pin.