MOSFET specs help portable-system designers

EDN Europe, 17 Aug 2007

17th August 2007 – Vishay has announced a series of power MOSFETs which it claims specify, for the first time, operating conditions with 1.2-V gate-to-source voltage. The TrenchFET devices bring the MOSFET turn-on voltage into alignment with the 1.2-V to 1.3-V operating voltages of digital ICs used in mobile electronics, and can eliminate an extra conversion stage in battery-operated systems with a core voltage lower than 1.8V, where that has been used to generate sufficient gate drive to fully-turn on earlier power switches. In MOSFETs where 1.5V is the lowest rating, on-resistance tends to increase exponentially at lower, unspecified gate-to-source voltages such as 1.2V, Vishay says. The 1.2-V TrenchFETs offer guaranteed low n-channel on-resistance as low as 0.041 Ohms and p-channel on-resistance as low as 0.095 Ohms at a 1.2-V gate drive. On-resistance performance at a 1.5-V gate drive is better than in devices for which 1.5V is the lowest gate-to-source specification: as low as 0.022 Ohms (n-channel) and 0.058 Ohms (p-channel). All of the above relates to a Vds value of 8V. In a variety of packages, the n-channel SiA414DJ (PowerPAK SC-70), Si8424DB (MICRO FOOT), and SiB414DK (PowerPAK SC75), and the p-channel SiA417DJ (PowerPAK SC-70), Si8429DB (MICRO FOOT), and SiB417DK (PowerPAK SC-75) are in this release. The previously released p-channel Si1499DH in the SC-70 package completes Vishay’s 1.2-V power MOSFET offerings.