Belgian microelectronics company Melexis has expanded its current-sensing portfolio with two new isolated current sensors, the MLX91224 and MLX91225, aimed at high-voltage automotive and industrial applications. The devices support plug-and-play current measurement up to 100A RMS, are natively compliant with ASIL B functional safety, and offer fast analog response, according to Chinese outlet D1EV.
Simplifying EV powertrain design
The new sensors are designed to simplify the design of electric vehicle powertrains, DC-DC converters, onboard chargers (OBC) and solar inverter systems. Traditional low-current sensing relies on shunt resistors, which introduce ohmic losses and require external isolation amplifiers, adding assembly complexity and calibration costs at the end of the production line.
The MLX91224 and MLX91225 integrate a low-impedance current conductor, Hall sensing elements, signal conditioning circuitry and an isolation barrier in a compact SOIC package. The current flows through the package's internal lead frame, and two Hall plates use a differential sensing architecture to capture the magnetic flux, suppressing external stray magnetic fields and providing a linear analog output proportional to the measured current. Depending on the package, the devices support working voltage isolation ratings up to 1640V RMS.
ASIL B safety and three package options
Melexis claims to be the first to bring an integrated current sensor platform with ASIL B compliance to high-voltage current measurement in automotive applications. The devices are developed according to the ISO 26262 standard as independent safety elements (SEooC), providing a reliable starting point for safety-related measurements in high-voltage automotive systems. They offer microsecond-level response for motor control, main drive inverters, DC-DC converters, AC/DC charging piles, solar inverters and power management modules.
The series comes in three package options to meet different current, isolation and surge requirements. The DE package (SOIC6FL) supports continuous current up to 50A RMS and includes overcurrent detection (OCD). The DG package (SOIC16W) offers similar current range and working voltage with increased creepage and clearance. The DH package (SOIC12W FL) extends continuous current capability to 100A RMS and provides a surge current rating up to ±29kA.
All models support AC and DC current measurement, unipolar or bipolar sensing, and ratiometric or fixed output configurations. The MLX91224 is designed for 5V systems, while the MLX91225 supports 3.3V systems, allowing flexible matching with different microcontroller architectures and supply voltage rails. The overcurrent detection function is available on a dedicated pin, with thresholds either preset internally or configured externally via the OCD-TH pin. The devices operate over a temperature range of -40°C to 150°C.
“Many of our customers are designing products that span different power levels, from low-power motor drives to high-current infrastructure,” said Bruno Boury, product line director at Melexis, in a statement. “The MLX91224 and MLX91225 provide them with a current sensor platform that can evolve smoothly as power requirements grow, while significantly simplifying the integration of electrical isolation, overcurrent protection and functional safety.”
According to D1EV, the launch extends Melexis's integrated current sensing product line to higher current ranges, strengthening the company's strategic focus on EV powertrains, electrification and sustainable power infrastructure. The devices are applicable across AC/DC charging piles, electric drive systems, DC-DC converters, solar inverters, data center power distribution units (PDU) and smart load control. Samples and evaluation boards for all three package options are now available.
