Infineon Announces Industry’s First 900 V Superjunction MOSFETs; Increases Efficiency in Power Supply, Industrial and Renewable Energy Applications

Infineon Technologies AG (FSE/NYSE: IFX) today introduced the industry’s first 900 V superjunction MOSFETs specifically intended for high-efficiency SMPS (switched-mode power supply), industrial and renewable energy applications. Continuing Infineon’s history of innovation in the power semiconductor industry, the new energy-saving CoolMOS™ 900 V power MOSFET family overcomes the “silicon limit” in power transistor manufacturing, and provides an alternative for high-voltage designs using standard TO (Transistor Outline) packages. With extremely low static and dynamic losses, the CoolMOS 900 V family enables design of more efficient and cost-effective topologies for such applications as LCD TVs, solar power generation systems, PC “silverbox” power supplies and lighting systems.

The Infineon CoolMOS family of power transistors uses an innovative technology approach to overcome 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. 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 are at least 75 percent lower than can be achieved in such packages using conventional 900 V MOSFETs. Because of the low R DS(on), the new CoolMOS 900 V devices can offer an FOM (figure-of-merit, calculated as on-state resistance times gate charge) as low as 34 ohms*nanocoulomb, which results in extremely low conduction, driving and switching losses, and leads to increased efficiency.

Expanded design possibilities in LCD TVs, PC “silverboxes,” solar power generation systems

The combination of high blocking voltage with low conduction and switching losses in the CoolMOS 900 V family enables designers to develop more efficient power system topologies for a wide range of applications. For example, quasi-resonant flyback designs for LCD TV power supplies can benefit from a higher flyback voltage, which provides a longer primary duty cycle with reduced peak current, true zero-voltage switching and significantly lower voltage stress on the secondary side. Because of their very low on-resistance, a single CoolMOS 900 V products in a TO-220-FP package can be used in such a design, rather than the two or more TO-220-FP packages that must be used with conventional 900V MOSFETS. Compared to the most common solution today, which uses 600 V MOSFETs, a CoolMOS 900V solution gives a premium efficiency of more than 0.5 percent.

CoolMOS 900 V devices can be used to design “silverbox” PC power supplies with a single-transistor forward (STF) topology, achieving the required high output power while still being compliant with the “80 PLUS program,” an industry initiative to ensure that PC power supplies are at least 80 percent efficient. The STF topology is easier to design, and has a simplified driver stage and reduced parts count, resulting in cost improvements without efficiency disadvantages, compared to such other solutions as two-transistor-forward topologies.

In solar power generating systems, more photovoltaic converter panels can be placed in series instead of in parallel if the MOSFET voltage is increased to 900 V. This series connection reduces cabling power losses and costs, with cabling costs alone cut by a factor of two when changing from 600 V to 900 V devices.

The new CoolMOS devices also allow improved design of PFC (Power Factor Correction) supplies and lighting ballasts, because they permit designers to accept a higher DC link or input voltage. For example, high-power applications that use three-phase PFC and PWM stages with DC link voltages of up to 750 V will see such benefits as higher power density from having the industry’s lowest R DS(on) in a small package, such as the TO-247.

Ballast designs for lamps that are fed from a three-phase mains supply, such as special discharge lamps used in comfort lighting and electronic lamp ballasts for street lights and greenhouse heating lamps, will also benefit from topologies based on the CoolMOS 900 V family.

Packaging, Availability and Price

CoolMOS 900 V family members will be available in several industry-standard packages, including best- in-class devices with R DS(on) of 120 mΩ, 340 mΩ and 1200 mΩ in TO-247, TO-220, TO-220FP and D-PAK packages, respectively. In addition, 500 mΩ, 800 mΩ and 1000 mΩ devices will be available.

Samples of the 340 mΩ device in TO-220, TO-220FP and TO-247 packages, and of the 1200 mΩ part in a D-PAK, are available now. The volume price for a best-in-class 120 mΩ part in a TO-247 package will be below US$3.50 (Euro 2.40).

Infineon is showing its new family of CoolMOS 900 V power semiconductors in Booth #611 at the Applied Power Electronics Conference (APEC), February 24 - 28, 2008, in Austin, Texas.

For further information, please see www.infineon.com/power and www.infineon.com/coolmos