INA149AMDREP

The INA149 is a high-precision unity-gain differential amplifier with a wide input common-mode voltage range. It is a single monolithic device that includes a high-precision operational amplifier and an integrated thin-film resistor network. The INA149 can accurately measure small differential voltages when common-mode signals up to ±275 V are present. The inputs of the INA149 are protected against instantaneous common-mode or differential overloads up to 500 V. In many applications where current isolation is not required, the INA149 can replace isolation amplifiers. This feature eliminates the need for an expensive isolated input power supply and removes associated ripple, noise, and quiescent current. The INA149's excellent 0.0005% nonlinearity and 500 kHz bandwidth make it superior to traditional isolation amplifiers. The INA149 is pin-compatible with high common-mode voltage amplifiers such as the INA117 and INA148 and offers better performance than these two devices. The INA149 is available in a small-outline integrated circuit (SOIC)-8 package. This device is rated for operation over a temperature range of -55°C to +125°C.

Applications

• High-voltage current sensing
• Battery voltage monitoring
• Power supply current monitoring
• Replacement for motor control isolation circuits

Key features

• Common-mode voltage range: ±275 V
• Minimum CMRR: 84 dB from -55°C to ±125°C
• DC specification maximum offset voltage: 3500 μV
• Maximum gain error: 0.047%
• Maximum gain nonlinearity: 0.001% FSR at 25°C
• AC performance bandwidth: 500 kHz
• Typical slew rate: 5 V/μs
• Wide supply voltage range: ±2.0 V to ±18 V
• Maximum quiescent current: 1100 μA
• Output swing on ±15-V supply: ±13.5 V
• Input protection common-mode voltage: ±500 V
• Differential voltage: ±500 V