Low-Cost, Precision, High-Side Current-Sense Amplifier

Low-cost, Precision Current Monitoring For Portable Battery-Powered Applications


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 critical. 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 current-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 functions 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 single resistor, accommodating a wide range of battery voltages and currents.

An open-collector power-good output (active-low PG) indicates when the supply voltage reaches an adequate level to guarantee proper operation of the current-sense amplifier. The MAX4172 operates with a 3.0V to 32V supply voltage, and is available in a space-saving, 8-pin µMAX® or SO package.

MAX4172: Functional Diagram MAX4172: Functional Diagram Enlarge+

Key Features

  • Ideal for High-Side Monitoring
    • 3V to 32V Supply Operation
    • ±0.5% Typical Full-Scale Accuracy Over Temperature
    • High Accuracy +2V to +32V Common-Mode Range, Functional Down to 0V, Independent of Supply Voltage
    • 800kHz Bandwidth [VSENSE = 100mV (1C)]
    • 200kHz Bandwidth [VSENSE = 6.25mV (C/16)]
  • Minimizes Board Space Requirements
    • µMAX and SO Packages


  • Battery-Powered Applications
  • Closed-Loop Battery Chargers/Current Sources
  • Energy Management
  • Portable PCs: Notebooks, Subnotebooks, Palmtops
  • Portable Test/Measurement Systems
  • Portable/Cellular Phones
  • Smart Battery Packs/Chargers
Part Number Output Format CMVR
Bi-Dir. Curr. Sense VSENSE_FS
VOS @25°C
Gain Gain Accuracy @25°C
Oper. Temp.
Package/Pins Budgetary
min max min max typ recomm. max max @ -3dB See Notes
MAX4172  Current 0 32 3 32 800 No 150 750 10 µA/mV 2 800 0 -40 to +85
$2.21 @1k
See All Current Sense Amplifiers (44)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Tools & Models

MAX4172 Macromodel
MAX4172 Orcad Library

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