Texas Instruments has introduced the TMCS2100-Q1, which it describes as the industry's first multiaxial coreless Hall-effect current sensor designed for hybrid electric vehicle and electric vehicle (HEV/EV) traction inverter applications. Hall-effect sensors detect electrical current by measuring the magnetic field it produces, and the TMCS2100-Q1 introduces a new approach that combines multiaxial measurement with a proprietary algorithm, aiming to eliminate the traditional trade-off between measurement precision and physical size in traction inverter designs.
Existing coreless current sensors are typically limited to measuring a magnetic field along a single axis, but the TMCS2100-Q1 is the first to measure magnetic fields in both horizontal and vertical directions simultaneously. This multiaxial approach is reportedly 20 times more accurate than single-axis alternatives, achieving displacement error, meaning inaccuracy caused by physical movement between the sensor and conductor, of less than 1% at 0.4mm of movement, and as low as 0.25% at 0.1mm. That level of precision improves the accuracy of the torque control loop in an EV's powertrain, helping maximize efficiency and power delivery across varying load and temperature conditions.
Jason Cole, vice president and general manager of sensing products at TI, said that for the first time, engineers have access to a Hall-effect current sensor that overcomes the limitations of existing solutions, something he described as especially important as 800V vehicle architectures raise the bar for how accurate traction inverter measurements need to be. He said the TMCS2100-Q1, developed using research from TI's Kilby Labs, the company's advanced R&D division, gives automakers a tool to build HEVs and EVs where tighter current measurement translates directly into longer driving range, smoother ride quality, and more efficient motor control.
The challenge this addresses is a persistent trade-off automakers face when trying to make traction inverters lighter and more efficient to extend range and improve performance. Traditional sensors that use a magnetic core, sometimes called C-core designs, offer strong accuracy but add size and weight. Coreless alternatives are smaller, but typically sacrifice precision due to displacement error and magnetic crosstalk, meaning interference from other nearby magnetic fields.
TI's new sensor addresses this trade-off in two main ways. First, by measuring both axes simultaneously: vibration during normal vehicle operation causes slight movement between the sensor and the conductor it's measuring, which typically degrades accuracy in single-axis coreless sensors. The TMCS2100-Q1 significantly reduces this vibration-induced error by measuring magnetic fields along both horizontal and vertical axes at the same time. Second, by maintaining overall measurement accuracy, which minimizes the influence of magnetic crosstalk and reduces torque ripple, an inconsistency in motor torque that can cause jerky acceleration, unwanted motor noise, and inefficient operation that reduces driving range.
By eliminating the need for a magnetic core without sacrificing precision, the TMCS2100-Q1 allows for smaller, more power-dense traction inverter designs, helping automakers build EVs that are more efficient, offer longer range, and drive more smoothly. TI positions this as the latest addition to its automotive product lineup, reflecting its continued investment in addressing engineering challenges across the vehicle.
On more technical details, Hall-effect current sensors work by detecting the magnetic field generated as electrical current flows through a busbar, the conductor that typically connects a traction inverter to the motor. Existing differential coreless sensors often require modifications to the busbar itself, such as notches, slices, or holes, which can complicate thermal management. By positioning multiple sensors relative to the busbar, TI's TMCS2100-Q1 avoids the need for any busbar modification altogether. This multi-sensor design also gives engineers more flexibility to adapt to different mechanical layouts and optimize how much board space is used, helping reduce the overall size of the traction inverter.
