Application-specific MOSFETs lower RDS(on) and footprint
The first 80V and 100V application-specific MOSFETs (ASFETs) have been announced by Nexperia. They are designed for hotswap with enhanced safe operating area (SOA) in a compact 8.0 x 8.0mm LFPAK88 package.
These ASFETs are optimised for demanding hot swap and soft start applications and are qualified to 175 degrees C for use in advanced telecomms and computing equipment.
Nexperia’s expertise in silicon and package development, the PSMN2R3-100SSE (100V, 2.3 mOhm N-channel ASFET) is tailored to meet the requirements of demanding hot swap applications.
Nexperia has also released PSMN1R9-100SSE (80V, 1.9 mOhm), an 80V ASFET is intended for use in 48V power rails in computing servers and other industrial applications where environmental conditions allow for MOSFETs with a lower BVDS (breakdown voltage) rating.
ASFETs have strong linear mode performance, essential to manage in-rush current effectively and reliably when capacitive loads are introduced to the live backplane. Low RDS(on) is also important to minimise I2R losses when the ASFET is fully turned on.
Despite the lower RDS(on) and compact package size, Nexperia said its third generation of enhanced SOA technology also achieves 10 per cent SOA improvement compared to previous generations in D2PAK packages (33A vs 30A at 50V at one millisecond).
Another innovation, said Nexperia, is that the new ASFETs have characterised SOA at both 25 and 125 degrees C. Fully tested, hot SOA curves are provided within the data sheets, removing the need for design engineers to perform thermal de-rating calculations, and significantly extending the useful hot SOA performance.
Until now, ASFETs for hot swap and computing applications were limited to much bigger D2PAK packages (16 x 10mm). LFPAK88 packages can replace D2PAK packages, providing up to 60 per cent space efficiency. The PSMN2R3-100SSE has an RDS(on) of only 2.3 mOhm, representing at least a 40 per cent reduction on currently available devices. According to Nexperia, this results in power density improvements of 58x, LFPAK88 also offers two times higher ID (max) current rating, low thermal and electrical resistance. The ASFETs also combine features of Nexperia’s silicon and copper clip packaging technologies, including a smaller footprint, lower RDS(on) and improved SOA performance. Nexperia also offers a range of 25, 30, 80 and 100V ASFETs in a 5.0 x 6.0mm LFPAK56E package, optimised for lower power applications where smaller PCB footprint is needed.
