MAX4172_12 Datasheet, PDF (1/9 Pages) Maxim Integrated Products – Low-Cost, Precision, High-Side Current-Sense Amplifier

MAX4172
Low-Cost, Precision, High-Side
Current-Sense Amplifier
_______________General Description
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.
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.
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.
________________________Applications
Portable PCs: Notebooks/Subnotebooks/Palmtops
Battery-Powered/Portable Equipment
Closed-Loop Battery Chargers/Current Sources
Smart-Battery Packs
Portable/Cellular Phones
Portable Test/Measurement Systems
Energy Management Systems
__________________Pin Configuration
TOP VIEW
+
RS+ 1
RS- ²
N.C. 3
MAX4172
N.C. 4
8 V+
7 PG
6 OUT
5 GND
____________________________Features
o Low-Cost, High-Side Current-Sense Amplifier
o ±0.5% Typical Full-Scale Accuracy Over
Temperature
o 3V to 32V Supply Operation
o High Accuracy +2V to +32V Common-Mode
Range, Functional Down to 0V, Independent of
Supply Voltage
o 800kHz Bandwidth [V_SENSE = 100mV (1C)]
200kHz Bandwidth [V_SENSE = 6.25mV (C/16)]
o Available in Space-Saving µMAX and SO
Packages
______________Ordering Information
PART
TEMP. RANGE PIN-PACKAGE
MAX4172ESA+ -40°C to +85°C 8 SO
MAX4172EUA+ -40°C to +85°C 8 µMAX
+Denotes a lead(Pb)-free/RoHS-compliant package.
__________Typical Operating Circuit
UNREGULATED
DC SUPPLY
3V TO 32V
LOW-COST
SWITCHING
REGULATOR
R_SENSE
50mΩ
V_SENSE
0 TO 32V
2A
ANALOG OR
LOGIC SUPPLY
RS+
RS-
V+
PG
MAX4172
100kΩ
POWER GOOD
LOAD/
BATTERY
OUT
GND
FEEDBACK LOOP
V_OUT = 500mV/A
I_OUT =
V_SENSE / 100Ω
R_OUT
1kΩ
µMAX/SO
µMAX is a registered trademark of Maxim Integrated Products, Inc.
LOW-COST BATTERY CHARGER/CURRENT SOURCE
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