High-power MOSFETs enhance current sharing and reduce design complexity

Nexperia has released the latest additions to its expanding portfolio of application-specific MOSFETs (ASFETs), whose features have been tailored to meet the exacting requirements of specific end applications. The 80V PSMN1R9-80SSJ and 100V PSMN2R3-100SSJ switches have been designed to deliver enhanced dynamic current sharing in high-power 48V applications that need the use of several closely matched MOSFETs connected in parallel. These include motor drives in EVs, such as forklifts, e-scooters, and mobility devices, as well as high-power industrial motors.

When connecting two or more MOSFETs in parallel to support high current capability and lower conduction losses, it can be challenging for designers to ensure that the load current is shared equally between individual devices during turn-on and turn-off. MOSFETs with the lowest VGS(th) will turn on first, causing higher thermal stress, resulting in accelerated failure. To provide a sufficient safety margin, engineers often over-specify the MOSFETs employed in their end applications. This expensive and time-consuming approach typically requires additional testing yet still cannot provide guarantees on how devices will behave at higher load currents (tens of Amps). An alternative approach is to request tightly matched devices from a supplier; however, this can further increase the cost of the end application.

The features of the ASFETs eradicate the necessity for designers to adopt either of these approaches by providing improved dynamic current sharing. These switches offer a 50% lower current delta between parallel devices (for currents up to 50A per device) at turn-on/off and provide a VGS(th) window that is up to 50% lower (0.6V min-to-max). This benefit, combined with the low RDS(on) of 1.9mΩ or 2.3mΩ helps to deliver high efficiency in power switching applications.

The new ASFET devices are available in the rugged, space-efficient 8mm x 8mm copper-clip LFPAK88 package, delivering an operating temperature range from -55C to +175C.