Texas Instruments INA199C2RSWR

Overview

INA199C2RSWR 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 100 V/V fixed gain, ±150 μV maximum offset voltage, –0.1 V to 26 V common-mode input range, 100 μA max quiescent current, 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 management and Qi wireless charging transmitters.

For engineers reviewing the INA199C2RSWR datasheet, INA199C2RSWR pinout, INA199C2RSWR application, or INA199C2RSWR equivalent, this page delivers verified technical context, package-specific pin functions, real-world design implications of its zero-drift architecture, and validated alternative options for current-sense amplifier selection in space-constrained, thermally demanding embedded systems.

Technical Context

The INA199C2RSWR implements a zero-drift chopper-stabilized amplifier topology that achieves ±150 μV max offset and 0.5 μV/°C max drift over –40°C to +125°C, enabling accurate measurement at sub-20-mV shunt voltages. Its differential input stage supports bidirectional sensing across shunts placed on either side of the load, with independent operation from supply voltage via a –0.1 V to 26 V common-mode range.

It uses internal precision resistor networks (R1/R2 = 1 MΩ, R3/R4 = 10 kΩ) to set its fixed 100 V/V gain, delivering rail-to-rail output swing (to within 50 mV of V+ and 5 mV of GND) while maintaining 10 ppm/°C max gain drift and 100 dB min CMRR. The device draws only 100 μA max supply current and requires no external gain-setting components.

Key Specifications

Pinout & Package

INA199C2RSWR is housed in a 10-pin UQFN package (RSW) with wettable flanks, measuring 1.80 mm × 1.40 mm and 0.5-mm lead pitch. Thermal resistance is 107.3°C/W (junction-to-ambient), supporting operation up to 125°C ambient with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A2D and MAX40056ATA+T, the INA199C2RSWR uniquely balances 26-V common-mode capability, 2.7–26 V single-supply operation, and UQFN-10 size-making it optimal for cost-sensitive, space-constrained 12–24 V systems where full 48-V range or sub-50-μV offset are unnecessary.

Availability

INA199C2RSWR 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 RoHS-compliant packaging.

Supply support for INA199C2RSWR 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 amplifiers and power management ICs.

The INA199 series was designed specifically for high-accuracy, low-power current sensing in space-constrained consumer and industrial power systems-emphasizing zero-drift stability, wide common-mode operation, and minimal external component count.

FAQ

What is the maximum common-mode voltage the INA199C2RSWR can handle?

The INA199C2RSWR supports a common-mode input voltage range of –0.1 V to 26 V across its full operating temperature range (–40°C to +125°C). This specification applies specifically to the C-grade version (INA199C), enabling reliable high-side sensing on 24-V rails and low-side sensing near ground without requiring level-shifting circuitry. The device maintains functionality even when VIN+ exceeds the V+ supply voltage by up to 26 V.

Does the INA199C2RSWR require external gain-setting resistors?

No, the INA199C2RSWR does not require external gain-setting resistors. It integrates precision internal resistor networks (R1/R2 = 1 MΩ, R3/R4 = 10 kΩ) to deliver a fixed 100 V/V gain. This eliminates gain tolerance errors from external components, reduces PCB layout sensitivity, and ensures consistent performance across production units-critical for automated manufacturing of Qi wireless charging transmitters and notebook power modules.

How does the zero-drift architecture of the INA199C2RSWR improve current measurement accuracy?

The zero-drift chopper-stabilized architecture of the INA199C2RSWR delivers ±150 μV maximum input offset voltage and 0.5 μV/°C maximum offset drift over –40°C to +125°C. This enables accurate current sensing with as little as 10-mV full-scale shunt voltage-reducing shunt power dissipation by 90% compared to conventional 100-mV full-scale monitors-while maintaining <1% total error across temperature without factory calibration.

Can the INA199C2RSWR be used for bidirectional current sensing?

Yes, the INA199C2RSWR supports true bidirectional current sensing. When current flows from IN+ to IN−, the output voltage rises above the REF voltage; when current reverses direction, the output falls below REF. This polarity inversion allows direct detection of charge/discharge states in battery management systems and regenerative braking current in motor controllers-without requiring additional signal conditioning circuitry.

What is the recommended bypass capacitor for the INA199C2RSWR V+ pin?

A 0.1-μF ceramic capacitor placed as close as possible between the V+ and GND pins is the minimum recommended bypass for the INA199C2RSWR. For noisy supply environments-such as Qi transmitter DC-DC stages or telecom power converters-an additional 1-μF X7R capacitor in parallel improves high-frequency noise rejection. TI's SBOS469H datasheet specifies these values based on stability testing across 2.7–26 V supply and full temperature range.