TI's Two-Axis Current Sensor Targets EV Traction Inverters

Texas Instruments has introduced the TMCS2100-Q1, a coreless Hall-effect current sensor for hybrid and electric vehicle traction inverters that measures the magnetic field around a conductor on both the horizontal and vertical axes, with displacement error the company says stays under 1% at 0.4 mm of movement.

Texas Instruments (TXN) has put a new automotive current sensor on the market, and the interesting part is not the headline specification but the failure mode it is designed to eliminate. The TMCS2100-Q1 is a coreless Hall-effect sensor built for the traction inverters in hybrid and battery-electric vehicles, and instead of reading the magnetic field around a current-carrying conductor along a single axis, it reads it in both the horizontal and vertical directions. Texas Instruments says the resulting displacement error stays below 1% at 0.4 mm of movement.

That number describes a very specific engineering headache. A coreless Hall sensor infers current from the magnetic field a conductor produces, which means the measurement depends on exactly where the sensing element sits relative to the busbar. Move the two apart — through solder-joint tolerance, board flex, thermal expansion, or years of road vibration — and a single-axis reading drifts. Two-axis sensing gives the device a second view of the same field, so a shift that corrupts one component of the measurement can be compensated by the other.

Why a fraction of a millimetre matters in a traction inverter

The traction inverter is the box that turns the battery pack's direct current into the three-phase alternating current the motor actually uses. It is the single most electrically violent component in an EV powertrain, switching high currents thousands of times a second, and everything the vehicle does well or badly downstream of the pack depends on knowing what those currents are.

Phase-current measurement feeds motor control: torque accuracy, efficiency, how smoothly the car pulls away, how much regenerative braking energy is recovered. It also feeds protection. Overcurrent detection in an inverter has to be fast and it has to be trustworthy, because the alternative is either a shutdown that strands the driver or a switching device that fails at full power.

Sensor drift shows up in both roles. A measurement that reads a few percent low under thermal load quietly costs efficiency and range; one that reads high can trip protection thresholds that were never actually crossed. Because inverters are sealed, welded, potted assemblies that live for the life of the vehicle, a sensor that loses accuracy as its mechanical position shifts cannot be recalibrated in the field. Holding error inside 1% across 0.4 mm of movement, as Texas Instruments describes for the TMCS2100-Q1, is aimed squarely at that constraint, according to Charged EVs.

Coreless design removes iron, and adds a positioning problem

Current sensing in power electronics has historically taken one of a few routes. Shunt resistors are cheap and precise but sit in the current path and dissipate heat. Closed-loop and cored open-loop Hall sensors wrap a magnetic concentrator around the conductor, which improves signal strength and rejects stray fields but adds mass, cost, and the risk of magnetic saturation and hysteresis in the core itself.

Coreless designs strip out the iron. That makes them smaller, lighter, cheaper to build into a busbar assembly, and immune to core saturation — which matters when peak phase currents in a high-performance inverter run far above the continuous rating. The trade is sensitivity to geometry and to external magnetic fields. Two-axis sensing is one of the levers available to claw back the geometry half of that trade without reintroducing the core.

The "-Q1" suffix is the tell for where the part is meant to go: it is Texas Instruments' designation for devices qualified to automotive standards, meaning temperature range, reliability testing and production-part documentation aimed at Tier 1 suppliers who will not design in a commercial-grade component. A traction inverter design cycle runs years, so parts like this are sold into programs long before the vehicles reach showrooms.

An analog franchise leaning on the car

Texas Instruments' business is analog and embedded processing chips — the unglamorous silicon that measures, converts, drives and powers rather than computes — and automotive has been the growth story analog suppliers have leaned on as electrification multiplies the number of sensors, gate drivers and power-management parts per vehicle. An EV powertrain needs current sensing in the inverter, the on-board charger, the DC-DC converter and the battery management system. Each of those is an analog socket that did not exist in an internal-combustion car.

Competition for those sockets is dense. Current sensing pulls in the automotive magnetic-sensor specialists, the broad-line European and Japanese analog houses, and discrete shunt-and-amplifier approaches that Tier 1 designers can assemble themselves. Differentiation tends to come exactly where this launch is aimed: accuracy retained over temperature and mechanical tolerance, isolation ratings, and the amount of calibration work a customer can avoid.

Where the shares sat as the part was announced

Texas Instruments stock was firmer than the market on the day of the announcement. As of the last trade at 16:37 GMT on 27 August 2026, TXN changed hands at 266.78, up 1.91% from the previous close of 261.77, having traded between 261.10 and 267.48 during the session.

That outpaced the broad indices. The S&P 500, via the SPY exchange-traded fund, stood at $771.22, up 0.67% on the day; the Nasdaq 100 tracker QQQ was at $719.32, up 1.12%; and the Dow 30 fund DIA was at $536.00, up 0.33%. A single product release does not move a company of this size, and nothing in the day's trade should be read as a market verdict on one sensor. Semiconductor names moved broadly higher on the session.

What to watch from here

Three things determine whether a part like this matters commercially. The first is design wins — automotive components are validated over long qualification cycles, and revenue from a sensor announced in 2026 lands in later model years. The second is whether two-axis coreless sensing becomes the category standard, which would pull rival suppliers toward similar architectures and compress the advantage. The third is the direction of EV production volumes themselves, since content-per-vehicle gains only translate into analog revenue if the vehicles get built.

For inverter designers, the practical question is narrower and more immediate: does relaxed mechanical positioning tolerance let them simplify the busbar assembly, drop a calibration step, or shrink the module? That is where a specification measured in tenths of a millimetre turns into cost.

Key facts

• Product: TMCS2100-Q1 coreless Hall-effect current sensor from Texas Instruments
• Key specification: Displacement error under 1% at 0.4 mm of movement, per the company
• Application: Traction inverters in hybrid and battery-electric vehicles
• TXN last trade: 266.78, +1.91%, as of 16:37 GMT on 27 Aug 2026

Frequently asked questions

What is the TMCS2100-Q1?

It is a coreless Hall-effect current sensor introduced by Texas Instruments for hybrid and electric vehicle traction inverters. Unlike single-axis devices, it measures the magnetic field around a current-carrying conductor in both the horizontal and vertical directions. Texas Instruments says displacement error remains below 1% at 0.4 mm of movement between sensor and conductor.

Why does two-axis sensing improve accuracy?

A coreless Hall sensor infers current from the strength of the magnetic field around a conductor, so the reading depends on the exact position of the sensing element. Solder tolerance, board flex, thermal expansion and vibration can shift that position. Reading two axes gives the device a second view of the same field, allowing it to compensate for movement that would distort a single-axis measurement.

What does a traction inverter do in an electric vehicle?

The traction inverter converts the battery pack's direct current into the three-phase alternating current that drives the motor. It switches high currents at high frequency, and accurate phase-current measurement is what allows precise torque control, efficient operation, effective regenerative braking, and fast overcurrent protection of the switching devices.

What does the -Q1 suffix mean on a Texas Instruments part?

It is the company's designation for components qualified to automotive requirements, covering temperature range, reliability testing and the production documentation that vehicle suppliers demand. Tier 1 automotive suppliers generally will not design in commercial-grade silicon, so the qualification marking is a prerequisite for use in a production powertrain.

How is a coreless sensor different from a cored Hall sensor?

Cored designs wrap a magnetic concentrator around the conductor, boosting signal strength and rejecting stray fields, but adding mass, cost and the risk of core saturation and hysteresis. Coreless designs remove the iron, making the sensor smaller and cheaper and immune to saturation, at the cost of greater sensitivity to positioning and to external magnetic fields.

How did Texas Instruments shares trade on the day of the announcement?

As of the last trade at 16:37 GMT on 27 August 2026, TXN was at 266.78, up 1.91% from a previous close of 261.77, with a session range of 261.10 to 267.48. That was ahead of the broad market, where the S&P 500 tracker SPY rose 0.67% and the Nasdaq 100 tracker QQQ rose 1.12%.

Sources

• TI’s TMCS2100-Q1 sensor measures current on two axes in EV traction inverters — Charged EVs

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