Texas Instruments INA240A1PW

Overview

INA240A1PW from Texas Instruments is a bidirectional, ultra-precise current sense amplifier optimized for high-noise PWM environments. It features 20 V/V fixed gain, ±25 μV max input offset voltage, 132-dB DC CMRR, –4 V to 80 V common-mode range, and operates from 2.7–5.5 V supply. It enables accurate low-side and high-side current sensing in motor control power stages.

For engineers reviewing the INA240A1PW datasheet, INA240A1PW pinout, INA240A1PW application, or INA240A1PW equivalent, this page delivers verified specifications, package-validated pin functions, real-world use cases in solenoid and actuator systems, and two confirmed alternative parts with documented technical and application differences.

Technical Context

The INA240A1PW employs a zero-drift architecture with enhanced PWM rejection circuitry that suppresses large ΔV/Δt transients-critical in motor drives where fast-switching FETs induce >50-kHz common-mode noise. Its dual-reference-pin interface (REF1/REF2) supports configurable unidirectional or bidirectional output midpoints without external op-amps.

It integrates matched internal resistors for reference divider accuracy (0.02% typical), achieves 400 kHz bandwidth at 20 V/V gain, and maintains 93-dB AC CMRR at 50 kHz-enabling stable current measurement during PWM dead-time transitions and flyback recovery in solenoid drivers.

Key Specifications

Pinout & Package

INA240A1PW is housed in an 8-pin TSSOP (PW) package measuring 3.00 mm × 4.40 mm, with exposed thermal pad for improved power dissipation in compact motor driver PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A2PW, the INA240A1PW provides lower gain for improved noise immunity and larger shunt compatibility; compared with MAX40056ASA+, it delivers superior PWM rejection and negative common-mode operation-making it uniquely suited for industrial motor and solenoid control.

Availability

INA240A1PW is available at Aetrix Electronics and suitable for motor controls, solenoid valve systems, and telecom power management requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for INA240A1PW 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 power management ICs.

The INA240 family was designed specifically for high-reliability current sensing in harsh PWM environments-including industrial motor drives, solenoid actuators, and telecom power systems-where common-mode transients and wide voltage ranges challenge conventional amplifiers.

FAQ

What is the maximum common-mode voltage the INA240A1PW can handle?

The INA240A1PW supports a common-mode input voltage range from –4 V to 80 V. This allows it to accurately sense current during inductive flyback events (e.g., solenoid de-energization) where the shunt voltage dips below ground, and also operate safely on 48-V telecom or 24-V industrial buses without external level shifting. The –4 V rating is explicitly specified in Section 7.3 of the SBOS662C datasheet.

Does the INA240A1PW require external components for basic operation?

No-INA240A1PW operates with only a supply decoupling capacitor (0.1 µF ceramic, placed within 1 cm of VS and GND pins). Its zero-drift architecture eliminates the need for external offset trim, and its fixed 20 V/V gain removes requirement for external gain-setting resistors. Reference pins (REF1/REF2) may be tied together and grounded for unidirectional use, or biased to VS/2 for bidirectional operation-no additional active circuitry is necessary.

Can the INA240A1PW be used for bidirectional current sensing?

Yes-the INA240A1PW supports true bidirectional current sensing via its dual reference inputs (REF1 and REF2). When both pins are tied to VS/2, the output centers at 2.5 V (with 5-V supply), allowing symmetric positive/negative current representation. This configuration is validated in Section 8.4.3 and Figure 8-5 of the datasheet, and enables H-bridge current reconstruction without external op-amps or level shifters.

What is the purpose of the NC pin on the INA240A1PW TSSOP package?

Pin 1 of the INA240A1PW in the PW (TSSOP-8) package is labeled NC (No Connection) and has no internal bond wire or circuit connection. Per Table 6-1 and Figure 6-1 in the SBOS662C datasheet, it may be left floating or connected to GND for mechanical stability-neither choice affects electrical performance, thermal behavior, or EMI characteristics.

How does the enhanced PWM rejection in the INA240A1PW improve system reliability?

The enhanced PWM rejection in the INA240A1PW reduces output transient artifacts during large common-mode voltage steps (e.g., >100 V/µs), as demonstrated in Figures 7-21 and 7-22. This prevents false overcurrent triggers in motor protection logic, eliminates ADC sampling corruption during PWM dead time, and maintains closed-loop stability-directly improving functional safety compliance and reducing field failure rates in industrial drives.