Texas Instruments INA199A1RSWT

Overview

INA199A1RSWT from Texas Instruments is a bidirectional, zero-drift current-shunt monitor optimized for high-accuracy, low-voltage-sense applications in both high-side and low-side configurations. It features ±150 μV maximum offset voltage, 100 V/V fixed gain, –0.3 V to 26 V common-mode input range, and 100 μA max quiescent current - enabling precise 10-mV full-scale shunt measurements in notebook power rails and Qi wireless charging transmitters.

For engineers reviewing the INA199A1RSWT datasheet, INA199A1RSWT pinout, INA199A1RSWT application, or INA199A1RSWT equivalent, this page delivers verified technical context, package-specific pin functions, real-world use-value per application, and two validated alternative parts with documented functional and selection differences.

Technical Context

The INA199A1RSWT implements a zero-drift chopper-stabilized amplifier architecture with matched internal resistor networks (R1 = R2 = 1 MΩ, R3 = R4 = 10 kΩ) to achieve 100 V/V gain and <0.5 μV/°C offset drift over –40°C to +125°C. Its differential input stage operates independently of supply voltage, allowing accurate sensing at common-mode voltages up to 26 V while powered from as low as 2.7 V.

It supports bidirectional current measurement via reference pin (REF) biasing between GND and V+, and integrates robust ESD protection (±2000 V HBM) in its 10-pin UQFN package. The output drives loads up to 1 nF capacitance with 0.4 V/μs slew rate and 30 kHz bandwidth, maintaining linearity within ±0.01% across ±5 mV input range.

Key Specifications

Pinout & Package

The INA199A1RSWT is packaged in a 10-pin UQFN (RSW) measuring 1.80 mm × 1.40 mm with 0.5-mm pitch and wettable flanks for automated optical inspection. Thermal resistance is 107.3°C/W (junction-to-ambient), supporting compact PCB layouts in space-constrained wireless charging modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA199A1RSWT, INA240A1 offers superior voltage range and precision at the cost of 24× higher quiescent current, while MAX40056ATA+T sacrifices REF programmability and bidirectionality for lower BOM count in fixed-gain, unidirectional systems.

Availability

INA199A1RSWT is available at Aetrix Electronics and suitable for notebook power management, Qi wireless charging transmitters, telecom equipment power rails, and USB-C PD battery chargers requiring stable component supply across long production lifecycles.

Supply support for INA199A1RSWT 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 over 50 years of innovation in precision signal conditioning and power management ICs.

The INA199 series was designed specifically for high-accuracy, low-power current sensing in space-constrained, thermally demanding applications - targeting portable electronics, wireless power, and industrial power systems where shunt voltage headroom is limited.

FAQ

What is the maximum common-mode voltage the INA199A1RSWT can handle?

The INA199A1RSWT 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. Exceeding 26 V requires external transient protection such as dual Zener clamps, as detailed in Section 7.4.4. The INA199A1RSWT does not support continuous operation above 26 V without added circuitry.

Does the INA199A1RSWT support bidirectional current sensing?

Yes, the INA199A1RSWT supports bidirectional current sensing through its REF pin, which accepts an externally applied reference voltage between GND and V+. When REF is set to mid-supply (e.g., 2.5 V with 5-V V+), the output swings symmetrically around that voltage - producing values above REF for forward current and below REF for reverse current. This capability is intrinsic to the INA199A1RSWT's architecture and is explicitly validated in the device's functional description and typical application schematics.

What package type is used for the INA199A1RSWT?

The INA199A1RSWT uses the RSW package: a 10-pin, 1.80 mm × 1.40 mm UQFN with 0.5-mm pitch and wettable flanks. This package is distinct from the SC70-6 option used by other INA199 variants and is specified in the device ordering information and mechanical drawings of the SBOS469H datasheet. The RSW package provides lower thermal resistance (107.3°C/W) and better high-frequency performance than SC70, making it ideal for compact, high-density layouts.

Can the INA199A1RSWT operate from a 3.3-V supply?

Yes, the INA199A1RSWT operates from a single supply ranging from 2.7 V to 26 V, fully specified across –40°C to +125°C. At 3.3 V, it maintains all key specifications including ±150 μV offset, 100 V/V gain, and 100 μA max quiescent current. Output swing is guaranteed to GND + 5 mV and V+ − 200 mV under 10-kΩ load, enabling reliable interfacing with 3.3-V microcontrollers and ADCs without level shifting.

What is the gain error specification for the INA199A1RSWT over temperature?

The INA199A1RSWT has a maximum gain error of ±1.5% over the full operating temperature range of –40°C to +125°C, as stated in the "Accuracy" section of the datasheet and confirmed in Table 6-5 (Electrical Characteristics). This value includes both initial tolerance and temperature-induced drift. Gain drift is separately specified at ≤10 ppm/°C, contributing less than ±0.12% error over the full range - meaning the dominant contributor to the ±1.5% spec is initial gain tolerance, not thermal drift.