Smart low-side switches replace mechanical relays and MOSFETs

Smart low-side switches replace mechanical relays and MOSFETs

New Products |
By Christoph Hammerschmidt

Semiconductor manufacturer Rohm has unveiled a new generation of 40V intelligent low-side switches in single- and dual-channel configurations that combine thermal rejection with low on-resistance during switching by controlling the number of current-carrying channels using proprietary TDACC (Thermal Distributed Active Clamp Circuit) technology. This makes them the industry’s first two-channel TDACC product to offer 40 mΩ on-resistance in a compact SOP-J8 package.

The growing number of electronic components and digitalisation in cars are leading to the need to reduce the size of application solutions and reduce BOMs. In addition, global issues such as CO₂ emissions and worldwide trends such as autonomous driving are leading to more stringent requirements and more complex architectures that demand a higher level of safety and robustness. Traditional discrete solutions with mechanical relays or MOSFETs can no longer meet these requirements and do not provide protection against system failures. These requirements pave the way for Intelligent Power Devices (IPD)….

Rohm is now building on its wide existing range of devices designed according to its one smart power process. Integrated over-temperature, over-current and over-voltage protection, built-in diagnostics and microcontroller feedback ensure improved performance and reliability, as well as longer life than discrete solutions.

The BV1LExxxEFJ-C and BM2LExxxFJ-C family products are intelligent low-side devices that integrate all the above aspects and can switch currents for all types of resistive, capacitive or inductive loads. When an inductive load is switched off, the power MOSFET inside the smart switch must dissipate all the magnetic energy previously stored in the coil’s magnetic field. During this time, the device protects itself by actively limiting the voltage to a safe level. The dissipated power generates heat that is distributed on the surface of the integrated power MOSFET. Rohm’s new IPDs are the first in the industry to combine heat suppression with low on-resistance by controlling the number of current-carrying channels using proprietary TDACC (Thermal Distributed Active Clamp Circuit) technology. TDACC improves integration capability and enables the industry’s first two-channel product with 40 mΩon-resistance to be launched in the compact SOP-J8 package.

The family offers a wide range of on-resistance values (40/80/160/250 mΩ) in single-channel and dual-channel configurations to meet a wide range of customer requirements. In addition, the contact discharge tolerance of all products in the family is higher than other standard products. This ensures safer operation in various electronic devices.

The profile of the new intelligent switches makes them particularly suitable for use in body control modules (BCMs), interior and exterior lighting, motors, transmissions and other electrical systems in motor vehicles.

The components will be available from Rohms online distribution partners such as Digi-Key, Mouser and Farnell from February 2023, with distribution through other online retailers planned.



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