Texas Instruments' INA225 is a voltage-output, current-sense amplifier that senses drops across current-sensing resistors at common-mode voltages that can vary from 0 to 36 V, independent of the supply voltage. The device is a bidirectional, current-shunt monitor that allows an external reference to be used to measure current flowing in both directions across a current-sensing resistor.
Four discrete gain levels are selectable using the two gain-select terminals (GS0 and GS1) to program gains of 25 V/V, 50 V/V, 100 V/V, and 200 V/V. The low-offset, zero-drift architecture and precision gain values enable current-sensing with maximum drops across the shunt as low as 10 mV of full-scale, while maintaining very high accuracy measurements over the entire operating temperature range.
The device operates from a single +2.7 V to +36 V power supply, drawing a maximum of 350 µA of supply current. The device is specified over the extended operating temperature range (–40°C to +125°C), and is offered in an MSOP-8 package.
- Wide common-mode range: 0 V to 36 V
- Offset voltage: ±150 µV (Max, all gains)
- Offset voltage drift: 0.5 µV/°C (Max)
- Gain accuracy, over temperature (Max):
- 25 V/V, 50 V/V: ±0.15%
- 100 V/V: ±0.2%
- 200 V/V: ±0.3%
- 10 ppm/°C gain drift
- 250 kHz bandwidth (gain = 25 V/V)
- Programmable gains:
- G1 = 25 V/V
- G2 = 50 V/V
- G3 = 100 V/V
- G4 = 200 V/V
- Quiescent current: 350 µA (Max)
- Power supplies
- Motor control
- Telecom equipment
- Power management
- Test and measurement