INA240 Current-Sense Amplifiers

By Texas Instruments 63

INA240 Current-Sense Amplifiers

Texas Instruments' INA240 are voltage-output, current-sense amplifiers with enhanced PWM rejection that can sense drops across shunt resistors over a wide common-mode voltage range from -4 V to 80 V, independent of the supply voltage. The negative common-mode voltage allows the device to operate below ground, accommodating the flyback period of typical solenoid applications. Enhanced PWM rejection provides high levels of suppression for large common-mode transients (Δv/Δt) in systems that use PWM signals (such as motor drives and solenoid control systems). This feature allows for accurate current measurements without large transients and associated recovery ripple on the output voltage.

These devices operate from a single 2.7 V to 5.5 V power supply, drawing a maximum of 2.4 mA of supply current. Four fixed gains are available: 20 V/V, 50 V/V, 100 V/V, and 200 V/V. The low offset of the zero-drift architecture enables current sensing with maximum drops across the shunt as low as 10 mV full-scale. All versions are specified over the extended operating temperature range (-40°C to +125°C), and are offered in an 8-pin TSSOP package.

Features
  • Enhanced PWM rejection
  • Excellent CMRR:
    • 132 dB DC CMRR
    • 93 dB AC CMRR at 50 kHz
  • Wide common-mode range: -4 V to 80 V
  • Accuracy:
    • Gain:
      • Gain error: 0.20% (max)
      • Gain drift: 2.5 ppm/°C (max)
  • Offset:
    • Offset voltage: ±25 µV (max)
    • Offset drift: 250 nV/°C (max)
  • Available gains:
    • INA240A1: 20 V/V
    • INA240A2: 50 V/V
    • INA240A3: 100 V/V
    • INA240A4: 200 V/V
  • Quiescent current: 2.4 mA (max)
Applications
  • Motor controls
  • Solenoid and valve controls
  • Power management
  • Actuator controls
  • Pressure regulators
  • Telecom equipment

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