INA149 Difference Amplifier

Texas Instruments' high common mode voltage difference amplifier

Texas Instruments INA149 Difference Amplifier Texas Instruments' INA149 is a precision unity-gain difference amplifier with a high input common-mode voltage range. It is a single, monolithic device that consists of a precision op amp and an integrated thin-film resistor network. The INA149 can accurately measure small differential voltages in the presence of common-mode signals up to ±275 V. The INA149 inputs are protected from momentary common-mode or differential overloads of up to 500 V.

In many applications, where galvanic isolation in not required, the INA149 can replace isolation amplifiers. This ability can eliminate costly isolated input-side power supplies and the associated ripple, noise, and quiescent current. The excellent 0.0005% nonlinearity and 500-kHz bandwidth of the INA149 are superior to those of conventional isolation amplifiers. INA149 Datasheet

  Features   Applications
  • Common-mode voltage range: ±275 V
  • Minimum CMRR: 90 dB from –40°C to +125°C
  • Wide supply range: ±2.0 V to ±18 V
  • AC performance:
    • Bandwidth: 500 kHz
    • Typical slew rate: 5 V/µs
  • High-voltage current sensing
  • Battery cell voltage monitoring
  • Power-supply current monitoring
  • Motor controls
  • Replacement for isolation circuits

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Texas Instruments
Part Number
Part Number
Packaging Voltage - Supply,
Single/Dual (±)
INA149AIDR 296-30028-2-ND Tape & Reel 4 V ~ 36 V,
±2 V ~ 18 V
(0.154", 3.90mm width)
INA149 Datasheet
296-30028-1-ND Cut Tape
296-30028-6-ND Digi-Reel®

Evaluation Module
Texas Instruments
Part Number
Part Number
INA149EVM 296-30217-ND    •   Easy access to pertinent nodes with test points and terminal blocks
   •   Convenient input and output filtering
   •   Versatile pad for evaluation in current/sensing applications
   •   Reverse supply and overvoltage protection
   •   Advanced evaluation with prototype areas and SMA/SMB connector footprints
   •   Footprints for providing a flexible reference voltage
INA149EVM User's Guide