INA281-Q1: High-Precision Current-Sense Amplifier for Automotive Applications

Introduction:

The INA281-Q1 is a precision current sense amplifier specifically designed for the demanding requirements of automotive electronics. With AEC-Q100 qualification and a temperature range of –40 °C to +125 °C, this device is engineered to perform reliably in the harshest automotive environments.

Features:

AEC-Q100 Qualified: Meets the stringent standards for automotive electronics, ensuring reliable operation across the temperature grade 1 range.

Wide Common-Mode Voltage: Operates with a common-mode voltage range of –4 V to +110 V, accommodating a broad spectrum of measurement needs.

Excellent CMRR: Features a 120-dB DC CMRR and a 65-dB AC CMRR at 50 kHz for accurate current measurement in high common-mode voltage scenarios.

Accuracy: Offers a maximum gain error of ±0.5% and a gain drift of ±20 ppm/°C, with a typical offset voltage of ±55 µV and an offset drift of ±0.1 µV/°C.

Available Gains: Comes with five fixed gain options: 20 V/V, 50 V/V, 100 V/V, 200 V/V, and 500 V/V, catering to diverse current-sensing applications.

High Bandwidth and Slew Rate: Capable of handling high-speed applications with a bandwidth of 1.3 MHz and a slew rate of 2.5V/µs.

Low Quiescent Current: Operates efficiently with a low quiescent current of 1.5 mA, making it suitable for power-sensitive applications.

Applications:

The INA281-Q1 is suitable for a variety of automotive applications, including:

Automatic transmission control systems

Automotive HVAC compressor modules

Valve and motor actuators

Gasoline and diesel engine platforms

Pump control systems

The INA281-Q1 is designed to measure voltage drops across shunt resistors within a wide common-mode range. Its ability to operate below ground voltage allows for precise measurement of recirculating currents in half-bridge applications. The device's low offset voltage, small gain error, and high DC CMRR enable highly accurate current measurement. With a bandwidth of 1.3 MHz and an AC CMRR of 65 dB at 50 kHz, the INA281-Q1 is also suited for high-speed applications such as fast overcurrent protection.

Operating from a single 2.7-V to 20-V supply, the INA281-Q1 is available in a compact SOT-23 package with two pin-out variants, providing designers with flexibility and space efficiency in their automotive electronics designs.

Conclusion:

The INA281-Q1 is a robust and precise current-sense amplifier, tailored for the rigorous demands of automotive applications. Its combination of a wide common-mode range, high bandwidth, and excellent accuracy makes it a reliable choice for ensuring the efficient and safe operation of automotive systems.