Enhanced isolation integrated current sensor

     Melexis has announced new safety certifications (UL/IEC 62368-1) for the MLX91220 (5V) and MLX91221 (3V) current sensors. They can now be used in systems with higher voltage isolation requirements for SOIC8 (715V BI, 307V RI) and SOIC16 (1415V BI, 707V RI) packages. This upgrade expands the application scope and reduces the number of BoM components. Applications that require enhanced isolation include OBC and HVAC/ compressors.

     To ensure the safety and isolation of high-voltage Class 3 power supplies such as 800V EV battery packs and chargers, two isolation barriers must be implemented to reduce them to a low risk. So far, these devices have only qualified as basic (i.e., individual) isolation devices, which requires engineers to include additional elements such as isolation amplifiers in their designs.

     With the new UL/IEC 62368–1 certification (Materials Group I), engineers can now use the company's Hall effect sensors knowing that their enhanced isolation is sufficient to protect end users from the risk of high pressure without the need for additional isolation barriers. The new voltage rating is (contamination level 2):SOIC16 package: Basic isolation (BI) of 1415 V, enhanced isolation (RI) of 707 V; For the SOIC8 package, 715 V is used for basic isolation (BI) and 307 V for enhanced isolation (RI).

     Engineers who use equipment with additional isolation barriers can eliminate unnecessary isolation components. In addition, the design of only basic isolation allows revalidation as a strengthened isolation system without changing the BoM.

     Introducing this "upgrade" only in the form of further technical qualification enhances the value of the already acclaimed Hall effect sensor, simplifying the design and reducing the associated engineering effort and cost. The solution maintains its highly accurate, flexible and plug and play nature and provides enhanced security measures for a variety of applications such as automotive OBCs, DC-DC converters, high voltage chargers, renewable energy inverters, white goods and robotics.

     "With the new MLX91220 and MLX91221 certifications, we offer engineers the easiest path to enhanced isolation," said Bruno Boury, Product Line Director at Melexis. "We have upgraded 50 products for free, helping customers meet critical safety requirements with just one component, reducing production costs and packaging constraints."

     With its excellent reliability in automotive and industrial applications, the device further consolidates its market availability with this additional safety certification. Current sensors are available in cost-effective and miniaturized SOIC8 narrow-body and larger SOIC16 wide-body packages, with a leakage area of 4mm for the former and 8mm for the latter. Both devices have a bandwidth of 300kHz, a response time of just 2us, and a current range between 0-50A RMS, providing engineers with a high return on investment.