Infineon Introduces 900V Superjunction MOSFETs
Infineon Technologies AG introduced what it claims is the industry’s first 900V superjunction MOSFETs specifically intended for high-efficiency SMPS (switched-mode power supply), industrial and renewable energy applications. The new energy-saving CoolMOS™ 900V power MOSFET family is said to overcome the "silicon limit" in power transistor manufacturing, and to provide an alternative for high-voltage designs using standard TO (Transistor Outline) packages. With low static and dynamic losses, the CoolMOS 900V family is said to enable 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 what is described as 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 RDS(on) (on-state resistance). In overcoming the silicon limit, the CoolMOS 900V devices achieve what is claimed to be the industry’s lowest RDS(on) per package type. On-state resistances of 0.12Ω in a TO-247 package, 0.34Ω in a TO-220 package and 1.2Ω in D-PAK packages are said to be at least 75% lower than can be achieved in such packages using conventional 900V MOSFETs.
The combination of high blocking voltage with low conduction and switching losses in the CoolMOS 900V 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 900V 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.
CoolMOS 900V 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% 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.
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 to 900V devices.
CoolMOS 900 V family members will be available in several industry-standard packages, including best- in-class devices with RDS(on) of 120, 340 and 1200mΩ; in TO-247, TO-220, TO-220FP and D-PAK packages, respectively. In addition, 500, 800 and 1000Ω devices will be available.
Samples of the 340mΩ device in TO-220, TO-220FP and TO-247 packages, and of the 1200mΩ part in a D-PAK, are available now. The volume price for a best-in-class 120mΩ part in a TO-247 package will be below US$3.50 (€2.40).
