New Industry Products

Nexperia Launches Application Specific MOSFETs for Automotive Applications

January 14, 2021 by Gary Elinoff

The dual MOSFET repetitive avalanche AEC-Q101 qualified devices are pre-tested for one billion cycles

Nexperia’s new application specific FET (ASFET) portfolio is aimed at automotive powertrain applications. Designed to control automotive inductive loads including actuators and solenoids, the units facilitate turn off times up to four times faster, and  allow for simpler designs by enabling a lower BOM


Nexperia Launches Application Specific MOSFETs for Automotive Applications Figure
Image courtesy of Nexperia


MOSFET-based designs for controlling the inductive loads have been based on active clamps, boost converters, external free-wheel diodes. The alternative, represented by this portfolio of devices, is a repetitive avalanche design that makes use of the internal blocking diode that is a basic characteristic of every MOSFET.


Nexperia Backs ASFETs

Nexperia backs the premise of “Optimizing MOSFETs to fit specific applications”, as described by Chris Boyce, Senior Director for the Power MOSFETs Group at Nexperia. As noted in an earlier article, the philosophy revolves around fabricating application specific FETs (ASFETs), or specific MOSFETs for specific jobs. Nexperia features ASFET lines for hotswap, power-over-internet, battery isolation and DC motor control, as well as this line specifically designed to deal with repetitive avalanche currents without overheating

As explained by Nexperia’s Product Manager, Richard Ogden “Typically, engineers looking to implement repetitive avalanche topologies have had to rely on devices that use older, planar semiconductor technologies. Offering automotive-qualified devices with guaranteed repetitive avalanche capabilities that are based on higher performance silicon structures will increase the number of powertrain designs that can take advantage of repetitive avalanche functionality.” 


Nexperia’s Automotive Repetitive Avalanche ASFET Product Family

Members of this product line offer operating efficiencies comparable to active clamp modalities,  but without the requirements for external components such as diodes. And, when compared to boost technologies, Nexperia estimates that designers can save up to 30% of the required board space due to a likely reduction of as many as 15 components.

The AEC-Q101 qualified units operate at temperatures of up to 175 °C, and are offered in 40 and and 60 volt versions. Typical RDS(ON) specifications range from 12.5 to 55 mΩ. To save further space, these dual MOSFETS are offered in Nexperia’s LFPAK56D (Dual Power-SO8) copper-clip packages. The resilient package, sized at approximately 5 by 4.5 mm, features gull wing leads that facilitate automated optical inspection (AOI) and also enable enhanced board stability.


Featured Products

Nexperia offers the BUK9K13-60RA, the BUK9K35-60RA and the BUK9K52-60RA. They are up-to-date trench MOSFETs, the modern alternative to older planar technologies. These dual N-channel devices featuring RDS(ON)’s of 12.5 mΩ, 35 mΩ and 55 mΩ, respectively. The company offers a series of informative videos that explain device operation and also offer design advice. 


Nexperia Launches Application Specific MOSFETs for Automotive Applications Figure
Image courtesy of Nexperia 


These three devices all feature a VDS of 60 volts


  Maximum Drain Current (ID)

Total Power

Typical Gate Drain Charge (QGD) Typical RDS(ON) Maximum Avalanche Ruggedness
BUK9K13-60RA 40 Amps 64 Watts 7.9 nC 10 mΩ 75.2 mJ
BUK9K35-60RA 22 Amps 38 Watts 3 nC 30.5 mΩ 28.6 mJ
BUK9K52-60RA 16 Amps 32 Watts 2.3 nC 47.3 mΩ 19.5 mJ


The avalanche ruggedness figure noted above refers to repetitive drain-source avalanche energy. It is central to application of these devices, and the figure comes with many caveats.



Nexperia’s Automotive ASFETs for Repetitive Avalanche will find use in: 

  • 12, 24 and 48 Volt automotive systems 
  • Transmission controlling
  • Engine controlling
  • Actuator and auxiliary loads