Hall current sensor delivers sigma-delta output
The Melexis MLX91229 Hall current sensor provides a second-order sigma-delta digital output that improves signal integrity in EV traction inverter applications. Optimized for automotive systems, this output tolerates heavy EMI, helping maintain signal integrity over longer PCB traces or wiring where electrical noise can introduce disturbances between the sensor and MCU.
Unlike analog sensors, the MLX91229 encodes measured current into a sigma-delta bitstream, with information represented by the density of digital pulses rather than absolute voltage levels. This encoding makes the signal inherently more resistant to electrical noise during transmission to the MCU. Because demodulation is performed in the host MCU, designers can optimize the tradeoff between fast overcurrent detection and high-accuracy current measurement.
Supporting current sensing from 200 A to 2000 A, the MLX91229 measures peak magnetic fields from 11 mT to 400 mT. It uses Manchester-encoded data transmission over differential RS-422 or LVDS interfaces. The AEC-Q100-qualified sensor operates over an ambient temperature range of –40°C to +125°C and is powered from a selectable 3.3-V or 5-V supply.
The MLX91229 is available in a 4-pin SIP through authorized distributors and is designed as a drop-in replacement for conventional analog sensors.
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