Texas Instruments INA199A2RSWT

Overview

INA199A2RSWT from Texas Instruments is a bidirectional, zero-drift current-shunt monitor optimized for high-accuracy, low-power current sensing in both high-side and low-side configurations. It features a 100 V/V fixed gain, ±150 μV maximum offset voltage, –0.3 V to 26 V common-mode input range, and operates from 2.7 V to 26 V supply. It enables precise 10-mV full-scale shunt measurements in notebook power rails and Qi wireless charging transmitters.

For engineers reviewing the INA199A2RSWT datasheet, INA199A2RSWT pinout, INA199A2RSWT application, or INA199A2RSWT equivalent, key selection considerations include its 100 V/V gain accuracy (±1.5% over temperature), 0.5 μV/°C offset drift, SC70-6 and UQFN-10 package options, and compatibility with low-voltage microcontroller ADC interfaces requiring rail-to-rail output swing.

Technical Context

The INA199A2RSWT implements a zero-drift chopper-stabilized amplifier architecture to achieve ultra-low offset and drift, enabling accurate current measurement at sub-10-mV shunt drops. Its differential input stage rejects common-mode voltages up to 26 V independent of supply voltage, supporting direct connection to battery or bus rails.

It uses internal precision resistor networks (R1/R2 = 1 MΩ, R3/R4 = 10 kΩ) to set its fixed 100 V/V gain, with guaranteed gain error ≤ ±1.5% across –40°C to +125°C. The device delivers 30 kHz bandwidth and 0.4 V/μs slew rate while consuming only 100 μA quiescent current.

Key Specifications

Pinout & Package

INA199A2RSWT is available in the 10-pin UQFN (RSW) package (1.80 mm × 1.40 mm, 0.5-mm pitch) and 6-pin SC70 (DCK) package (2.00 mm × 1.25 mm). The RSW variant provides dual IN+ and dual IN− pins for improved layout symmetry and lower parasitic impedance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA199A2RSWT, INA219AIDR reduces BOM count via integrated ADC but adds firmware dependency, while MAX40056AUT+T offers superior speed and offset but sacrifices high-voltage operation and temperature stability.

Availability

INA199A2RSWT is available at Aetrix Electronics and suitable for notebook computers, Qi-compliant wireless charging transmitters, and telecom equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for INA199A2RSWT 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The INA199 series was designed specifically for precision, low-power current sensing in space-constrained portable and power-management systems-emphasizing zero-drift accuracy, wide common-mode operation, and minimal board footprint.

FAQ

What is the maximum common-mode voltage supported by the INA199A2RSWT?

The INA199A2RSWT supports a common-mode input voltage range of –0.3 V to 26 V across its full operating temperature range (–40°C to +125°C). This specification applies specifically to the INA199A version, as confirmed in Section 6.5 of the SBOS469H datasheet. The device maintains functionality even when VIN+ exceeds the V+ supply rail by up to 26 V, making it suitable for high-side sensing on 24-V industrial buses or battery inputs.

Does the INA199A2RSWT support bidirectional current measurement?

Yes, the INA199A2RSWT supports bidirectional current sensing through proper biasing of the REF pin. When REF is tied to mid-supply (e.g., V+/2), the output swings symmetrically above and below that level-positive current yields OUT > REF, negative current yields OUT < REF. This behavior is explicitly documented in the "Bidirectional Sensing" section of the datasheet and validated in typical application circuits using dual-supply or single-supply with reference buffering.

What package options are available for the INA199A2RSWT?

The INA199A2RSWT is offered in two packages: the 6-pin SC70 (DCK) package (2.00 mm × 1.25 mm) and the 10-pin UQFN (RSW) package (1.80 mm × 1.40 mm). Both are RoHS-compliant, lead-free, and qualified for industrial temperature operation. The RSW package includes duplicated IN+ and IN− pins to reduce layout-induced mismatch and improve high-frequency performance-details confirmed in Figure 5-2 and Table 5-1 of the SBOS469H datasheet.

How does the gain error specification of the INA199A2RSWT compare to other versions in the family?

The INA199A2RSWT has a maximum gain error of ±1.5% over temperature (–40°C to +125°C), which is specified for all INA199A variants (A1/A2/A3). This differs from the INA199B and INA199C versions, which specify ±1.5% and ±1%, respectively. The "A2" suffix denotes the 100 V/V gain variant within the A-grade accuracy bin, and this ±1.5% limit is verified in electrical characteristics tables under "Gain error" in Section 6.5.

Can the INA199A2RSWT operate from a 3.3-V supply while monitoring a 12-V rail?

Yes, the INA199A2RSWT can operate from a 3.3-V supply while accurately monitoring a 12-V common-mode rail. Its common-mode input range (–0.3 V to 26 V) is independent of supply voltage, and its internal architecture rejects supply variations. The device draws only 100 μA from the 3.3-V rail, and output swing remains functional (GND + 5 mV to 3.3 V – 200 mV), as verified in Section 6.5 "Voltage Output" and Figure 6-6 of the SBOS469H datasheet.