ROHM’s new compact smart low side switches

The growing number of electronic components and digitalisation of various types of equipment are driving the need to shrink the application solution size and reduce the bill-of-materials (BOM). Besides, global issues such as CO2 emissions, or global trends such as autonomous driving, lead to stricter requirements and more complex architectures that demand an increased safety and robustness level. Conventional discrete solutions involving mechanical relays or MOSFETs can no longer meet these requirements and cannot provide protection against system failures. With greater demand for high integration, added safety features, built-in intelligence and diagnostic features, Intelligent Power Devices (IPD), also called smart switches, become an essential part of electronic systems in a continuously growing market.

ROHM addressed these market needs early on – by having developed a dedicated Smart Power process in 2014. Bringing together innovation, power-efficient technology, process optimisation, and analogue design experience, allows ROHM to offer a broad line-up of high-performance products. The integrated over-temperature, over-current and over-voltage protections, built-in diagnostic features and micro-controller feedback grant enhanced performance and reliability, superior lifetime, and reliability over discrete solutions.

The BV1LExxxEFJ-C and BM2LExxxFJ-C family of products are intelligent low side devices that integrated all of the above and can switch currents for any type of resistive, capacitive, or inductive loads. When switching off an inductive load, the power MOSFET inside the smart switch needs to dissipate all the magnetic energy stored previously in the inductor’s magnetic field. During this time the device protects itself by actively clamping the voltage to a safe level. The power dissipated generates heat that is distributed on the integrated power MOSFET’s surface. ROHM’s new products are the industry’s first to combine heat suppression with low ON resistance, by optimally controlling the number of current-carrying channels using proprietary TDACC circuit and device technology. TDACC™ offers increased integration capability, allowing ROHM to report the industry’s first 2-channel 40mΩ (ON resistance) product in the compact SOP-J8 package.

A wide range of ON-resistance values (40/80/160/250mΩ) in both 1-channel and 2-channel configurations are offered to meet diverse customer needs. Furthermore, the contact discharge tolerance of all the products in the family is higher than that of other standard products. This adds to a safer operation inside various electronic equipment types.

Taking advantage of the TDACC technology, ROHM will continue to develop intelligent power devices with lower ON resistance and a higher level of feature integration. This will allow ROHM to expand its product portfolio confirming its high-quality commitments towards customer needs with higher-performance products, increased functionality, outstanding energy efficiency, cost reduction, and higher safety.