Rohm’s compact intelligent (smart) low side switches reduce power loss and enable safer operation
Rohm’s compact intelligent low side switches replace mechanical relays and mosfets, fulfilling functional safety requirements in automotive and industrial equipment applications.
The new generation of one-channel and two-channel 40V intelligent (smart) low side switches are called the BV1LExxxEFJ-C and BM2LExxxFJ-C series. The two product families 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).
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 growing market.
Rohm addressed these market needs by developing a dedicated smart power process in 2014. Bringing together innovation, power efficient technology, process optimisation and analogue design experience allowed Rohm to offer a broad line-up of high-performance products. It claimed 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 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.
According to Rohm, these 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 two-channel 40mOhm (ON resistance) product in the compact SOP-J8 package.
A wide range of ON-resistance values (40/80/160/250mΩ) in both one-channel and two-channel configurations are offered to meet diverse customer needs. According to the company, the contact discharge tolerance of all the products in the family is higher than that of other standard products, which adds to a safer operation inside various electronic equipment types.
Application examples include: BCMs (body control modules), interior/exterior lamps, engine, transmission, and other automotive electrical systems; and industrial equipment such as PLCs (programmable logic controllers).
They are suitable for a wide range of applications in addition to the automotive and industrial systems.
