MOSFETs get their 15 minutes of fame at APEC

One thing you can count on at the power-conversion industry’s annual APEC (Applied Power Electronics Conference) show is that MOSFETs will be prominently featured. This year was no exception, with new announcements from Infineon, Fairchild, and Toshiba, among others.

Infineon is claiming an industry-first with its 900 V superjunction MOSFETs which target for high-efficiency SMPS (switched-mode power supply), industrial and solar energy applications. Infineon claims the CoolMOS 900 V power MOSFET family overcomes the “silicon limit,” a characteristic of MOSFET semiconductors in which doubling of voltage blocking capability leads to a five-fold increase in R DS(on) (on-state resistance). In overcoming the silicon limit, the CoolMOS 900 V devices achieve the industry’s lowest R DS(on) per package type, with on-state resistances of 0.12 ohm in a TO-247 package, 0.34 ohm in a TO-220 package and 1.2 ohms in D-PAK packages, which the company claims are at least 75 percent lower than conventional 900 V MOSFETs. The devices offer a figure-of-merit (calculated as on-state resistance times gate charge) as low as 34 ohms*nanocoulomb, yielding low conduction, driving, and switching losses, and increased efficiency. The volume price for a 120 mΩ part in a TO-247 package will be below US$3.50.

Using discrete MOSFETs on a board can increase manufacturing costs as well as introduce greater resistance between parts. Fairchild attacked this problem by incorporating two PowerTrench MOSFETs and a high current gate driver into its EPM15- packaged Power-SPM FPP06R001, which replaces as many as 10 discrete components. Fairchild claims the advanced package accounts for 10 percent lower on-resistance than comparable discrete solutions, and 16 percent lower stray inductance. (US$ 5.00 each.)

Toshiba announced new family of high-speed switching MOSFETs based on UMOS VI-H, the company’s sixth-generation trench process. The new devices enable increased power efficiency by lowering RDS(ON) as well as increasing switching speed through lower gate charge (QSW) and lower gate resistance (RG). The new MOSFETs also feature Aluminum Strap (Al-Strap) connections instead of conventional wire bond technology to further reduce RDS(ON). Toshiba is aiming the new family as the low-side MOSFET in DC-DC converter applications. Here are the specs: Drain-source voltage (VDSS) of 30V (max.), drain current (ID) of 50A (max.), RDS(ON) of 2.0milliohm (m§Ù) (typ.). One of the packaging options is a low-profile SOP Advance measureing 5mm x 6mm x 0.95mm. Pricing as low as $0.65.

The importance of discrete semiconductors in power efficient designs is becoming increasingly clear, and makes you wonder if companies like Texas Instruments and  National Semiconductor, which spun its discrete analog parts out into Fairchild several years ago, would be better served now if they had their own MOSFET group to best tailor their switching components to their control electronics.