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

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.

Applications

* 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

* 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