The INA281-Q1 is a high-precision current sense amplifier that can measure voltage drops across shunt resistors over a wide common-mode range from –4 V to 110 V. The negative common-mode voltage allows the device to operate below ground, thus accommodating precise measurement of recirculating currents in half-bridge applications. The combination of a low offset voltage, small gain error and high DC CMRR enables highly accurate current measurement. The INA281-Q1 is not only designed for DC current measurement, but also for high-speed applications (like fast overcurrent protection, for example) with a high bandwidth of 1.3 MHz and an 65-dB AC CMRR (at 50 kHz).
The INA281-Q1 operates from a single 2.7-V to 20-V supply, drawing 1.5 mA of supply current. The INA281-Q1 is available with five gain options: 20 V/V, 50 V/V, 100 V/V, 200 V/V, and 500 V/V. These gain options address wide dynamic range for current-sensing applications.
The INA281-Q1 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.
| Product type | Analog output |
| Common-mode voltage (max) (V) | 110 |
| Common-mode voltage (min) (V) | -4 |
| Input offset (±) (max) (µV) | 150, 200, 250, 300, 500 |
| Input offset drift (±) (typ) (µV/°C) | 0.07 |
| Voltage gain (V/V) | 20, 50, 100, 200, 500 |
| CMRR (min) (dB) | 120 |
| Bandwidth (kHz) | 900, 1000, 1300 |
| Supply voltage (max) (V) | 20 |
| Supply voltage (min) (V) | 2.7 |
| Iq (max) (mA) | 2.25 |
| Number of channels | 1 |
| Comparators (#) | 0 |
| Gain error (%) | 0.5 |
| Gain error drift (±) (max) (ppm/°C) | 20 |
| Slew rate (V/µs) | 2.5 |
| Features | High precision, Low-side Capable |
| Rating | Automotive |
| TI functional safety category | Functional Safety-Capable |
| Operating temperature range (°C) | -40 to 125 |
| SOT-23 (DBV) | 5 | 8.12 mm² 2.9 x 2.8 |