New power MOSFETs offer industry-low on-resistance down to 43-mohms at 4.5-V in smallest chipscale MICRO FOOT package

November 30, 2012 // By Paul Buckley
Vishay Intertechnology, Inc. has introduced new 12 V and 20 V n-channel and p-channel TrenchFET power MOSFETs with the industry's lowest on-resistance in the industry's smallest CSP form factor: the 0.8 mm by 0.8 by 0.4 mm MICRO FOOT package.

The devices released will be used for battery or load switching in power management applications for portable electronics such as smartphones, tablet PCs, and mobile computing devices. The MOSFETs' compact outlines save PCB space and provide ultra-thin profiles to enable slimmer and lighter portable electronics while their low on-resistance translates into lower conduction losses for reduced power consumption and longer battery life between charges. The devices' low on-resistance also means a lower voltage drop across the load switch to prevent unwanted undervoltage lockout.

For the first time in this form factor, the MOSFETs are built on an ultra-high-density technology that uses self-aligning process techniques to pack one billion transistor cells into each square inch of silicon. When combined with MICRO FOOT's packageless CSP technology, this provides the lowest on-resistance possible for a given outline area.

For n-channel devices, the result is a 43 mΩ maximum on-resistance at a 4.5 V gate drive for the 12 V Si8806DB. When a 20 V rating is needed, the Si8812DB offers a maximum on-resistance of 59 mΩ. The n-channel devices are optimal for high-speed switching applications with fast turn-on/off times of < 100 ns, such as DC/DC boost converter applications.

The -20 V p-channel Si8817DB and Si8489EDB are optimized for buck converter applications. With 76 mΩ maximum on-resistance at a 4.5 V gate drive, the smaller 0.8 mm by 0.8 by 0.4 mm Si8817DB will be used for applications where space is even more critical than on-resistance. The 1 mm by 1 mm Si8489EDB will be used when the lower maximum on-resistance of 54 mΩ at 4.5 V is more critical.

The Si8489EDB is the first p-channel Gen III device in the 1 mm by 1 mm form factor, and it provides 2500 V typical ESD protection. In addition, the Si8817DB offers on-resistance ratings down to 1.5 V, allowing the device to work with the lower-voltage gate drives and lower bus voltages common in