Low-Cost, SOT23, Voltage-Output, High-Side Current-Sense Amplifier

 

Part Number	Replacement	Explanation

Description

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The MAX4173 low-cost, precision, high-side current-sense amplifier is available in a tiny SOT23-6 package. It features a voltage output that eliminates the need for gain-setting resistors and it is ideal for today's notebook computers, cell phones, and other systems where current monitoring is critical. High-side current monitoring is especially useful in battery-powered systems, since it does not interfere with the ground path of the battery charger. The input common-mode range of 0 to +28V is independent of the supply voltage and ensures that the current-sense feedback remains viable even when connected to a battery in deep discharge. The MAX4173's wide 1.7MHz bandwidth makes it suitable for use inside battery charger control loops.

The combination of three gain versions and a user-selectable external sense resistor sets the full-scale current reading. This feature offers a high level of integration, resulting in a simple and compact current-sense solution.

The MAX4173 operates from a single +3V to +28V supply, typically draws only 420µA of supply current over the extended operating temperature range (-40°C to +85°C), and is offered in the space-saving SOT23 package.

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MAX4173F, MAX4173H, MAX4173T: Typical Operating Circuit Enlarge+

Key Features

• Low-Cost, Compact Current-Sense Solution
• High Accuracy +2V to +28V Common-Mode Range, Functional Down to 0V, Independent of Supply Voltage
• Three Gain Versions Available
  • +20V/V (MAX4173T)
  • +50V/V (MAX4173F)
  • +100V/V (MAX4173H)
• ±0.5% Full-Scale Accuracy
• ±3mV Input Offset Voltage (MAX4173T)
• Wide 1.7MHz Bandwidth (MAX4173T)
• 420µA Supply Current
• Available in Space-Saving SOT23 Package

Applications/Uses

• Cell Phones
• General System/Board-Level Current Monitoring
• Notebook Computers
• PA Bias Control
• Portable Battery-Powered Systems
• Power-Management Systems
• Precision Current Sources
• Smart Battery Packs/Chargers