These sensors can now be used in systems with higher voltage isolation requirements for both SOIC8 (715V BI, 307V RI) and SOIC16 (1415V BI, 707V RI) packages. This certification broadens their application range and reduces the Bill of Materials (BoM) component count. Applications that demand reinforced isolation include on-board chargers (OBC) and HVAC/compressor.
To ensure the safety and isolation of high-voltage class 3 energy sources, such as 800V EV battery packs and chargers, two isolation barriers are required to mitigate risk. Previously, the MLX91220 and MLX91221 were only qualified as basic isolation devices, necessitating the inclusion of additional components like an isolation amplifier in designs.
With the new UL/IEC 62368-1 certification (material group I), engineers can now confidently use Melexis Hall-effect sensors, assured that their reinforced isolation is sufficient to protect users from high voltage risks without additional isolation barriers. The new voltage ratings, for pollution degree 2, are:
- SOIC16 package: 1415V for basic isolation (BI) and 707V for reinforced isolation (RI)
- SOIC8 package: 715V for basic isolation (BI) and 307V for reinforced isolation (RI)
Engineers currently employing the MLX91220 or MLX91221 with extra isolation barriers can now remove these unnecessary components. Additionally, designs with only basic isolation can now be re-qualified as reinforced isolated systems without any changes to the BoM.
This technical qualification upgrade enhances the value of the Hall-effect sensors, simplifying designs and reducing engineering efforts and costs. This solution not only maintains high accuracy, flexibility, and plug-and-play nature but also offers reinforced safety measures for applications such as automotive OBC, DC/DC converters, high voltage chargers, renewable energy inverters, white goods, and robotics.
“With the new MLX91220 and MLX91221 qualification, we are providing engineers with the simplest route to reinforced isolation,” said Bruno Boury, Product Line Director at Melexis. “We have effectively upgraded 50 product variants at no cost to the customer, helping them achieve critical safety requirements with just a single component – easing production costs and packaging constraints.”
With its established reliability in automotive and industrial applications, the MLX91220 and MLX91221 further strengthen their market presence through this additional safety qualification. The current sensors are available in cost-effective and compact SOIC8 narrow bodies with 4 mm creepage and larger SOIC16 wide-body packages with 8 mm creepage. Both devices feature a bandwidth of 300 kHz, a rapid response time of 2 µs, and are available with a current range of 0-50 A RMS.
