ir3725 International Rectifier Corp., ir3725 Datasheet - Page 9

• Manufacturer Part Number: ir3725
• Description: Input Power Monitor With Digital Interface
• Manufacturer: International Rectifier Corp.

RESISTOR CURRENT SENSING APPLICATION
The voltage on the shunt resistor of the circuit below
is directly proportional to the current from the source.
Shunts developing 5 mV to 75 mV at I
used. Accuracy is enhanced at the higher voltage.
Select R
tolerance resistor. Sinking current capability of VCS1
or VCS2 is V
Page 9 of 19
T
to be a 25.5 kΩ 1% or better initial
IG
12 V Power
VDD
/ R
Source
T
.
VDD
Bypass
Cap
R
T
FS
have been
VT
Figure 2 Resistor Sensing Circuit
www.irf.com
VDD
R
CS1
IR3725
Chose R
either of them develops the same voltage that is
developed by the shunt at full scale current.
C
ceramic dielectric with a value between 0.1 μF and
10 μF.
CS2
VCS1
GND
is the integrator capacitor and should have a
SHUNT
C
CS2
CS1
and R
VCS2
R
CS2
CS2
SDA
SCL
VO
ALERT#
ADDR
such that this current through
IR3725
Data Sheet
2008_12_09