MAX4172
Low-Cost, Precision, High-Side
Current-Sense Amplifier
_______________General Description
____________________________Features
The MAX4172 is a low-cost, precision, high-side current-
sense amplifier for portable PCs, telephones, and other
systems where battery/DC power-line monitoring is criti-
cal. High-side power-line monitoring is especially useful in
battery-powered systems, since it does not interfere with
the battery charger’s ground path. Wide bandwidth and
ground-sensing capability make the MAX4172 suitable
for closed-loop battery-charger and general-purpose cur-
rent-source applications. The 0 to 32V input common-
mode range is independent of the supply voltage, which
ensures that current-sense feedback remains viable,
even when connected to a battery in deep discharge.
o Low-Cost, High-Side Current-Sense Amplifier
o ±±.ꢀ5 ꢁypical Full-Scale Accuracy ꢂver
ꢁemperature
o 3V to 32V Supply ꢂperation
o High Accuracy +2V to +32V Common-Mode
Range, Functional Down to ±V, Independent of
Supply Voltage
o 8±±kHz Bandwidth [V
= 1±±mV (1C)]
= 6.2ꢀmV (C/16)]
SENSE
SENSE
2±±kHz Bandwidth [V
o Available in Space-Saving µMAX and Sꢂ
To provide a high level of flexibility, the MAX4172 func-
tions with an external sense resistor to set the range of
load current to be monitored. It has a current output that
can be converted to a ground-referred voltage with a sin-
gle resistor, accommodating a wide range of battery volt-
ages and currents.
Packages
______________Ordering Information
An open-collector power-good output (PG) indicates
when the supply voltage reaches an adequate level to
guarantee proper operation of the current-sense amplifi-
er. The MAX4172 operates with a 3.0V to 32V supply
voltage, and is available in a space-saving, 8-pin µMAX®
or SO package.
PARꢁ
ꢁEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
MAX4172ESA+
MAX4172EUA+
8 µMAX
+Denotes a lead(Pb)-free/RoHS-compliant package.
________________________Applications
Portable PCs: Notebooks/Subnotebooks/Palmtops
Battery-Powered/Portable Equipment
Closed-Loop Battery Chargers/Current Sources
Smart-Battery Packs
__________Typical Operating Circuit
UNREGULATED
DC SUPPLY
3V TO 32V
R
SENSE
50mΩ
0 TO 32V
LOW-COST
SWITCHING
REGULATOR
2A
Portable/Cellular Phones
Portable Test/Measurement Systems
Energy Management Systems
V
ANALOG OR
LOGIC SUPPLY
SENSE
100kΩ
RS+
V+
RS-
PG
__________________Pin Configuration
POWER GOOD
LOAD/
BATTERY
MAX4172
TOP VIEW
+
I
V
=
OUT
OUT
8
7
6
5
1
2
3
4
V+
RS+
RS-
/ 100Ω
SENSE
GND
PG
MAX4172
FEEDBACK LOOP
= 500mV/A
V
OUT
OUT
GND
N.C.
N.C.
R
OUT
1kΩ
µMAX/Sꢂ
LOW-COST BATTERY CHARGER/CURRENT SOURCE
µMAX is a registered trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-1184; Rev 2; 10/12