New MOSFETs minimise derating and improve current sharing

Update: August 14, 2021

Nexperia has announced new 80V and 100V ASFETs with enhanced SOA performance, targeting hot-swap and soft-start applications in 5G telecom systems and 48V server environments and industrial equipment requiring e-fuse and battery protection.

ASFETs are a new breed of mosfet optimised for use in specific design scenarios. By concentrating on particular parameters crucial to an application, sometimes at the expense of others that are less important in the same design, new levels of performance can be reached. The new hot-swap ASFETs utilise a blend of the company’s latest silicon technology and copper-clip package construction to significantly strengthen the SOA and reduce the PCB area.

Previously, mosfets have suffered from the Spirito effect, where the SOA performance drops off swiftly due to thermal instability at higher voltages. The company’s rugged, enhanced SOA technology removes the ‘Spirito-knee’, increasing SOA by 166% at 50V compared to past generations in D2PAK.

Another important advancement is the inclusion of 125C SOA characteristics on the datasheet. Comments Mike Becker, senior international product marketing manager at Nexperia: “SOA is traditionally only specified at 25C, meaning designers have to derate for operation in hot environments. Our new hot-swap ASFETs include a 125C SOA specification, eliminating this time-consuming task and confirming Nexperia’s excellent performance even at elevated temperatures”.

The new PSMN4R2-80YSE (80V, 4.2mOhm) and PSMN4R8-100YSE (100V, 4.8mOhm) hot-swap ASFETs are packaged in the Power-SO8 compatible LFPAK56E. The unique internal copper-clip construction of the package enhances thermal and electrical performance while considerably decreasing footprint size. The new LFPAK56E products are only 5mm x 6mm x 1.1mm, offering reductions of 80% and 75% for PCB footprint and device height, respectively, compared to the D2PAK of previous generations. The devices also provide a maximum junction temperature of 175C, meeting IPC9592 regulations for telecoms and industrial applications.

Adds Becker: “A further benefit is improved current sharing in high power applications that demand multiple hot-swap MOSFETs to be used in parallel, improving reliability and reducing system cost. Nexperia is widely recognised as the market leader for hot-swap MOSFETs. With these latest ASFETs, we have again raised the bar.”