TEXAS INSTRUMENTS INA139NA/250 Current Sense Amplifier, SOT-23

The TEXAS INSTRUMENTS INA139NA/250 is a versatile, high-side current shunt monitor designed for accurate and efficient current sensing. It features a wide input common-mode voltage range and high-speed operation, powered by an exceptionally low quiescent current. This independent power-supply and input common-mode voltage capability allows for flexible circuit design and reliable performance in diverse applications.

A key advantage of this amplifier is its minimal power consumption, drawing only 60µA (typical) quiescent current. This low current draw enables the power supply to be connected to either side of the shunt resistor with negligible error, simplifying system design and improving accuracy. The device operates by converting a differential input voltage to a proportional output current, which is then converted back to a voltage using an external load resistor. This single external resistor provides the flexibility to set any desired gain from 1 to over 100, making the circuit highly adaptable.

While engineered for precise high-side current shunt measurement, the innovative architecture of the INA139 invites creative applications in signal measurement and level shifting scenarios. It provides a complete, unipolar current measurement solution in a compact, surface-mount package.

Key Features & Specifications

• Complete Circuit: Offers a full unipolar high-side current measurement solution.
• Independent Voltages: Supply and input common-mode voltages operate independently from 2.7V to 40V.
• Configurable Gain: Gain is easily set with a single external resistor (1 to 100+).
• Low Power: Features a very low quiescent current of 60µA (typical).
• High Performance: Delivers a gain bandwidth product of 440kHz and a high Common-Mode Rejection Ratio (CMRR) of 115dB.
• Compact Design: Housed in a space-saving SOT-23 surface-mount package with 5 pins.