The MAX4080/MAX4081 are high-side, current-sense amplifiers with an input voltage range that extends from 4.5V to 76V making them ideal for telecom, automotive, backplane, and other systems where high-voltage current monitoring is critical. The MAX4080 is designed for unidirectional current-sense applications and the MAX4081 allows bidirectional current sensing. The MAX4081 single output pin continuously monitors the transition from charge to discharge and avoids the need for a separate polarity output. The MAX4081 requires an external reference to set the zero-current output level (VSENSE= 0V). The charging current is represented by an output voltage from VREFto VCC, while discharge current is given from VREFto GND.For maximum versatility, the 76V input voltage range applies independently to both supply voltage (VCC) and common-mode input voltage (VRS+). High-side current monitoring does not interfere with the ground path of the load being measured, making the MAX4080/MAX4081 particularly useful in a wide range of high-voltage systems.The combination of three gain versions (5V/V, 20V/V, 60V/V = F, T, S suffix) and a user-selectable, external sense resistor sets the full-scale current reading and its proportional output voltage. The MAX4080/MAX4081 offer a high level of integration, resulting in a simple, accurate, and compact current-sense solution.The MAX4080/MAX4081 operate from a 4.5V to 76V single supply and draw only 75µA of supply current. These devices are specified over the automotive operating temperature range (-40°C to +125°C) and are available in a space-saving 8-pin µMAX® or SO package.Applications48V Telecom and Backplane Current MeasurementAutomotive (12V, 24V, or 42V Batteries)Avalanche Photodiode and PIN-Diode Current MonitoringBidirectional Motor ControlGeneral System/Board-Level Current SensingPower-Management SystemsPrecision High-Voltage Current Sources