Texas Instruments INA241B1IDR

Overview

INA241B1IDR from Texas Instruments is a bidirectional, ultra-precise current sense amplifier optimized for high-voltage switching systems, featuring 10V/V fixed gain, −5V to 110V operational common-mode range, ±0.1% max gain error, ±150µV max input offset voltage, and enhanced PWM rejection up to 125kHz - deployed in motor drives and cordless power tools for accurate inline current monitoring under fast transients.

For engineers reviewing the INA241B1IDR datasheet, INA241B1IDR pinout, INA241B1IDR application, or INA241B1IDR equivalent, this page delivers verified specifications, package mapping (SOIC-8), reference pin configuration for bidirectional output, thermal performance data (RθJA = 122.9°C/W), and real-world design context for high-CMRR current sensing in industrial and portable battery-powered systems.

Technical Context

The INA241B1IDR employs a zero-drift, multistage amplifier architecture enabling 1.1MHz bandwidth at all gains while maintaining 130dB typical DC CMRR and 89dB AC CMRR at 1MHz. Its enhanced PWM rejection circuitry holds output stability for 1µs during large ΔV/Δt common-mode transients, then relies on high AC-CMRR and bandwidth to suppress residual disturbances.

It supports bidirectional operation via dual reference pins (REF1/REF2), allowing programmable output mid-point offset (e.g., V_S/2 for ± full-scale swing); input bias current remains constant at 35µA (typ) across −20V to 120V survival common-mode range, independent of V_CM.

Key Specifications

Pinout & Package

INA241B1IDR is packaged in an 8-pin SOIC (D package), 4.9mm × 6mm body with standard gull-wing leads. Thermal resistance R_θJA = 122.9°C/W enables reliable operation at full ambient temperature range without forced airflow.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current sense amplifier applications.

Compared with INA240A1IDR and MAX40056ASA+T, the INA241B1IDR uniquely combines 125kHz PWM rejection, 1.1MHz bandwidth, and ±150µV offset in a single SOIC-8 package - making it the only option for precision bidirectional sensing in high-dV/dt, thermally constrained motor and actuator designs.

Availability

INA241B1IDR is available at Aetrix Electronics and suitable for motor drives, cordless power tools, and drone propulsion systems requiring stable component supply, long-term production continuity, and guaranteed traceable sourcing from Texas Instruments' authorized channel.

Supply support for INA241B1IDR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision signal conditioning and high-reliability industrial ICs.

The INA241x product line was designed specifically for high-accuracy, high-CMRR current sensing in electric motor control, battery management, and industrial actuation - addressing the need for robustness against fast common-mode transients in modern switching systems.

FAQ

What is the maximum common-mode voltage the INA241B1IDR can withstand during normal operation?

The INA241B1IDR operates reliably across a common-mode input range of −5V to 110V. This allows direct connection to high-side shunts in 48V, 60V, or 80V bus systems without level-shifting circuitry. Its survival rating extends to −20V to 120V, providing margin against load-dump or inductive kick transients encountered in automotive and industrial environments. The INA241B1IDR maintains specification compliance throughout this full operational range.

How does the enhanced PWM rejection feature of the INA241B1IDR improve system performance in motor control applications?

The INA241B1IDR's enhanced PWM rejection holds output stability for 1µs during fast common-mode transients (up to 125kHz), preventing false overcurrent readings that could trigger unnecessary shutdowns or torque distortion. In BLDC motor drives, this eliminates measurement corruption during MOSFET switching edges, enabling accurate current reconstruction for field-oriented control. The INA241B1IDR achieves this without external filtering, preserving signal bandwidth and reducing PCB area.

Can the INA241B1IDR be used for bidirectional current sensing, and how is the output configured?

Yes, the INA241B1IDR supports true bidirectional current sensing via its dual reference inputs (REF1 and REF2). To configure bidirectional operation, connect REF1 to V_S and REF2 to GND - setting the quiescent output to V_S/2. A positive shunt voltage produces output > V_S/2; negative shunt voltage yields output < V_S/2. This configuration is used in H-bridge motor controllers and regenerative braking circuits. The INA241B1IDR's matched internal resistor network ensures accurate mid-point referencing.

What is the thermal performance of the INA241B1IDR in SOIC-8 (D) package, and how does it affect design margins?

In the SOIC-8 (D) package, the INA241B1IDR has a junction-to-ambient thermal resistance (R_θJA) of 122.9°C/W. At 2.5mA supply current and 110V common-mode, self-heating remains below 1°C under typical PCB conditions (2-layer, 1oz copper). This allows full −40°C to 125°C ambient operation without derating, supporting deployment in sealed enclosures or high-temperature industrial settings. The INA241B1IDR's low quiescent power and stable offset vs. temperature further reduce thermal design complexity.

Does the INA241B1IDR require external components for stable operation, and what layout considerations are critical?

The INA241B1IDR is unity-gain stable and requires no external compensation. Critical layout practices include: (1) placing 0.1µF ceramic bypass capacitor between V_S and GND within 2mm of the pins; (2) routing IN+ and IN− as a tightly coupled differential pair away from noisy switching nodes; (3) grounding the NC pin; and (4) using separate low-impedance GND paths for power and signal. These practices preserve the INA241B1IDR's 130dB DC CMRR and prevent degradation of its 125kHz PWM rejection capability.