71m6521be Maxim Integrated Products, Inc., 71m6521be Datasheet - Page 60

• Manufacturer Part Number: 71m6521be
• Description: Energy Meter Ic
• Manufacturer: Maxim Integrated Products, Inc.

APPLICATION INFORMATION
Figure 28 and Figure 29 show how resistive dividers, current transformers, and restive shunts are connected to the voltage and
current inputs of the 71M6521BE.
All digital input pins of the 71M6521BE are compatible with external 5V devices. I/O pins configured as inputs do not require
current-limiting resistors when they are connected to external 5V devices.
Page: 60 of 97
V
in
See the cautionary note on the restrictions for combined SEG/DIO pins configured as digital inputs in the Digital I/O
Section.
VA = Vin * R
R
in
Figure 28: Resistive Voltage Divider (Left), Current Transformer (Right)
out
Connection of Sensors (CT, Resistive Shunt)
/(R
out
R
+ R
out
© 2005-2008 TERIDIAN Semiconductor Corporation
I
in
in
)
Connecting 5V Devices
Figure 29: Resistive Shunt
VA
Vout = R * I
R
I
in
core
1/N
in
V
I
V3P3
IA
out
out
Vout = R * I
I
in
R
Filter
Energy Meter IC
out
= R * I
V3P3
IA
V
71M6521BE
out
DATA SHEET
I
in
in
/N
JANUARY 2008
I
out
V1.0