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Texas Instruments INA281/INA281-Q1 Current Sense Amplifier

Texas Instruments INA281/INA281-Q1 Current Sense Amplifier can measure voltage drops across shunt resistors over a wide common-mode range from –4V to 110V. The negative common-mode voltage allows the device to operate below ground, thus accommodating precise measurement of recirculating currents in half-bridge applications. Combining a low offset voltage, small gain error, and high DC CMRR enables highly accurate current measurement. The Texas Instruments INA281/INA281-Q1 is not only designed for DC current measurement but also high-speed applications (like fast over current protection, for example) with a high bandwidth of 1.3MHz and a 65dB AC CMRR (at 50kHz).

The INA281/INA281-Q1 operates from a single 2.7V to 20V supply, drawing 1.5mA of supply current. The INA281/INA281-Q1 is available with five gain options: 20V/V, 50V/V, 100V/V, 200V/V, and 500V/V. These gain options address a wide dynamic range for current-sensing applications. The INA281 is specified over an operating temperature range of −40°C to +125°C and is offered in a space-saving SOT-23 package with two pin-out variants. The INA281-Q1 devices are AEC-Q100 qualified for automotive applications.

Features

  • Wide common-mode voltage
    • −4V to +110V operational voltage
    • −20V to +120V survival voltage
  • Excellent CMRR
    • 120dB DC CMRR
    • 65dB AC CMRR at 50kHz
  • Accuracy
    • Gain
      • ±0.5% (maximum) gain error
      • ±20ppm/°C (maximum) gain drift
    • Offset
      • ±55µV (typical) offset voltage
    • ±0.1µV/°C (typical) offset drift
  • Available gains
    • INA281A1,INA281B1 - 20V/V
    • INA281A2, INA281B2 - 50V/V
    • INA281A3, INA281B3 - 100V/V
    • INA281A4, INA281B4 - 200V/V
    • INA281A5, INA281B5 - 500V/V
  • 1.3MHz high bandwidth
  • 2.5V/µs slew rate
  • 1.5mA quiescent current

Applications

  • Active antenna system mMIMO (AAS)
  • Macro remote radio unit (RRU)
  • 48V rack server
  • 48V merchant network and server power supply (PSU)
  • Solenoid control
  • Valve control
  • Telecom equipment
  • Power supplies

Datasheets

Functional Block Diagram

Block Diagram - Texas Instruments INA281/INA281-Q1 Current Sense Amplifier

Related Development Tool

Texas Instruments INA281EVM Amplifier Evaluation Module (EVM)

Evaluates the INA281, a current sense amplifier with ten completely independent boards.

Learn Moreabout Texas Instruments INA281EVM Amplifier Evaluation Module (EVM) View Productsrelated to Texas Instruments INA281EVM Amplifier Evaluation Module (EVM)
Published: 2020-09-04 | Updated: 2024-08-19