Texas Instruments INA199A2RSWR

Overview

INA199A2RSWR 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 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 current sensing with as little as 10-mV full-scale shunt drop in notebook power rails and Qi wireless charging transmitters.

For engineers reviewing the INA199A2RSWR datasheet, INA199A2RSWR pinout, INA199A2RSWR application, or INA199A2RSWR equivalent, key selection criteria include its 100 V/V gain accuracy (±1.5% over temperature), 0.5 μV/°C max offset drift, SC70-6 and UQFN-10 package options, and suitability for battery charger current monitoring where low quiescent current (100 μA max) and wide common-mode range are critical.

Technical Context

The INA199A2RSWR implements a zero-drift chopper-stabilized amplifier architecture to achieve ultra-low offset and near-zero drift over –40°C to +125°C. Its differential input stage rejects common-mode voltages up to 26 V independent of supply voltage, enabling direct sensing on high-voltage rails while powered from low-voltage logic supplies.

It delivers 100 V/V fixed gain via internal precision resistor ratios (R3 = 10 kΩ, R4 = 1 MΩ), supports REF pin biasing from 0 V to V+, and provides rail-to-rail output swing (within 50 mV of V+ and 5 mV of GND at 10-kΩ load). Input bias current remains below 28 μA across its full common-mode range.

Key Specifications

Pinout & Package

INA199A2RSWR is packaged in a 10-pin UQFN (RSW) measuring 1.80 mm × 1.40 mm with 0.5-mm pitch and wettable flanks. The package supports automated optical inspection (AOI) and offers low thermal resistance (θ_JA = 107.3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA199A2RSWR, INA240A2DGNR extends common-mode capability for industrial 48-V rails but increases PCB area and cost, while MAX40056ATA+T delivers superior offset performance in compact WLP form but restricts supply voltage to 5.5 V-making INA199A2RSWR the optimal balance of voltage range, accuracy, and UQFN miniaturization for 3.3–24-V consumer power systems.

Availability

INA199A2RSWR is available at Aetrix Electronics and suitable for notebook computers, Qi wireless charging transmitters, and telecom equipment requiring stable component supply across extended temperature and voltage ranges.

Supply support for INA199A2RSWR 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 specializing in analog and embedded processing technologies, with leadership in precision analog signal chains and power management ICs.

The INA199 series was designed specifically for high-accuracy, low-power current sensing in space-constrained, thermally demanding applications such as portable computing and wireless power, emphasizing zero-drift stability and wide common-mode operation.

FAQ

What is the maximum common-mode voltage the INA199A2RSWR can handle?

The INA199A2RSWR supports a common-mode input voltage range of –0.3 V to 26 V across its full operating temperature range of –40°C to +125°C. This specification applies specifically to the INA199A version, enabling reliable high-side sensing on 24-V industrial rails or low-side sensing with negative transients. Exceeding 26 V requires external Zener clamping per TI application note TIDU473.

Does the INA199A2RSWR require external gain-setting resistors?

No, the INA199A2RSWR has a factory-trimmed fixed gain of 100 V/V achieved through laser-trimmed internal thin-film resistors (R3 = 10 kΩ, R4 = 1 MΩ). No external components are needed to set gain, simplifying layout and eliminating resistor tolerance errors. Gain cannot be modified externally without compromising accuracy or violating absolute maximum ratings.

Can the INA199A2RSWR operate from a 3.3-V supply?

Yes, the INA199A2RSWR operates from a minimum supply voltage of 2.7 V, making it fully compatible with standard 3.3-V logic rails. At 3.3-V supply, its output swings within 50 mV of V+ and 5 mV of GND under 10-kΩ load, delivering usable dynamic range for 12-bit ADCs. Quiescent current remains ≤100 μA, preserving system efficiency.

How does the REF pin function in the INA199A2RSWR?

The REF pin sets the output common-mode voltage baseline: V_OUT = 100 × (V_IN+ − V_IN−) + V_REF. It accepts DC voltages from 0 V to V+, enabling single-ended output referenced to mid-supply (e.g., 1.65 V for 3.3-V systems) or differential output when paired with an ADC's negative input. External impedance on REF must be <10 Ω to preserve CMRR >100 dB.

Is the INA199A2RSWR pin-compatible with other INA199 variants?

The INA199A2RSWR shares identical pinout and footprint with all RSW-package INA199 variants (e.g., INA199A1RSWR, INA199A3RSWR), differing only in gain (100 V/V vs 50/200 V/V) and specified gain error. No PCB redesign is needed when swapping between A1/A2/A3 versions in the same RSW package, though system-level gain calibration may be required due to variant-specific error bands.