76V, High-Side, Current-Sense Amplifiers with Voltage Output

 

Part Number	Replacement	Explanation

Description

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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 (V_SENSE = 0V). The charging current is represented by an output voltage from V_REF to V_CC, while discharge current is given from V_REF to GND.

For maximum versatility, the 76V input voltage range applies independently to both supply voltage (V_CC) and common-mode input voltage (V_RS+). 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.

MAX4080, MAX4081: Typical Operating Circuit Enlarge+

Key Features

• Ideal for High-Voltage Current Monitoring Applications
  • Wide 4.5V to 76V Input Common-Mode Range
  • Independent Operating Supply Voltage
• High Accuracy and Low Quiescent Current Support Precision Application Requirements
  • ±0.1% Full-Scale Accuracy
  • Low 100µV Input Offset Voltage
  • Three Gain Versions Available
    • 5V/V (MAX4080F/MAX4081F)
    • 20V/V (MAX4080T/MAX4081T)
    • 60V/V (MAX4080S/MAX4081S)
  • 75µA Supply Current (MAX4080)
• Flexible Current Sensing Supports Monitoring of Charge and Discharge of Batteries
  • Bidirectional (MAX4081) or Unidirectional(MAX4080) I_SENSE
  • Reference Input for Bidirectional OUT (MAX4081)
• Minimizes Required Board Space
  • 8-Pin µMAX Package

Applications/Uses

• 48V Telecom and Backplane Current Measurement
• Automotive (12V, 24V, or 42V Batteries)
• Avalanche Photodiode and PIN-Diode Current Monitoring
• Bidirectional Motor Control
• General System/Board-Level Current Sensing
• Power-Management Systems
• Precision High-Voltage Current Sources