A digital sensing approach promises cleaner current measurements, helping electric vehicle designers overcome electromagnetic noise without redesigning existing system layouts or hardware.
Melexis has begun shipping the MLX91229, a conventional Hall-effect current sensor featuring a sigma-delta digital output designed to improve signal integrity in electrically noisy environments. Supporting current sensing from 200A to 2,000A, the device is aimed at traction inverters and other automotive power electronics where electromagnetic interference can degrade conventional analogue sensor transmissions.
As electric powertrains adopt higher voltages and faster-switching silicon carbide (SiC) and gallium nitride (GaN) technologies, maintaining accurate current measurements becomes increasingly challenging. Unlike analogue implementations, which rely on small voltage variations vulnerable to interference, the sensor converts measured current into a sigma-delta bitstream, encoding information through the density of digital pulses rather than absolute voltage levels. This provides greater tolerance to transmission noise while preserving measurement accuracy at the receiving microcontroller.
The digital-output architecture helps reduce errors introduced along PCB traces and wiring, making it particularly suitable for traction inverter systems where high currents and rapid switching generate significant electromagnetic interference. Sharing the same footprint as existing analogue Hall-effect sensors, the device enables engineers to evaluate digital-output sensing without extensive redesign of system layouts or hardware.
The sensor also gives designers flexibility to select demodulation strategies that balance bandwidth, noise performance and response time according to application requirements. By combining improved signal integrity with drop-in compatibility, it offers an easier migration path from analogue to digital current sensing for demanding automotive and industrial applications.
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