Compact Intelligent (Smart) Low Side Switches: Reduced Power Loss and Safer Operation

­ROHM Semiconductor announced a new generation of single- and dual-channel 40 V intelligent (smart) low side switches, the BV1LExxxEFJ-C and BM2LExxxFJ-C series. The two product families are ideally designed for automotive and industrial applications. They are AEC-Q100 qualified and are suitable for systems such as car body control, engine and transmission control units, LED lighting modules or industrial PLC (programmable logic controllers).

The growing number of electronic components and digitalization of various types of equipment are driving the need to shrink the application solution size and reduce the bill-of-materials (BOM). In addition, global issues (e.g., CO2 emissions) and global trends (e.g., autonomous driving) lead to stricter requirements and more complex architectures that demand an increased level of safety and robustness. 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 for electronic systems in a continuously growing market.

ROHM addressed these market needs early on by developing a dedicated smart power process in 2014. Bringing together innovation, power efficient technology, process optimization and analog design experience, allows ROHM to offer a broad lineup of high-performance products. The integrated over-temperature, over-current and over-voltage protection, 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 integrate 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 (difficult to achieve in a compact size), 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 dual-channel 40mΩ (ON resistance) product in the compact SOP-J8 package.

A wide range of ON-resistance values (40/80/160/250mΩ) in both single- and dual-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.