Value-added performance and reduced cost of power conversion systems for motor drive and renewable energy applications

Reported by Cliff Keys, Editorial Director, Power Systems Design

These devices feature the industry's lowest device capacitance for any given current rating, enhancing overall system efficiency at higher switching frequencies and under light load conditions, the new thinQ! diodes help reduce overall power converter system costs.

Main application areas for SiC Schottky diodes are active Power Factor Correction (CCM PFC) in Switched-Mode Power Supplies (SMPS) and other AC/DC and DC/DC power conversion applications such as solar inverters and motor drives.

Compared to the second generation, the device capacitances of the Infineon third generation SiC Schottky diodes are about 40% lower, which reduces switching losses. For example in a 1kW PFC stage operating at 250kHz there will be an improvement of 0.4 percent in the overall efficiency under 20% load conditions.

Higher switching frequencies allow the use of smaller and lower cost passive components, such as inductors and capacitors, resulting in higher power density designs. Reduced power losses result in several benefits, including reduced cooling requirements in terms of size and number of heatsinks and fans, which enables system cost reduction and increased reliability levels. This also contributes to reduced system level energy requirements to provide an appropriate cooling environment. Infineon expects system cost reductions in some SMPS applications of up to 20%.

In addition to the ability to use smaller MOSFETs in an energy-efficient design, these products are extremely robust with extremely low failure rates monitored over the past five years.

Although at a system level, SiC delivers an impressively lower cost of ownership, we are still some years away from a diode-for-diode cost parity between silicon and SiC, commented Jan-Willem. However with all the other advantages considered, SiC enables a more dense and efficient design.

Jan-Willem explained further that Infineon was the world's first provider of SiC Schottky diodes, introducing its first products in 2001. During the last nine years, Infineon has made a number of significant improvements to its SiC Schottky diode technology in areas such as surge current stability, switching performance and in product cost, extending the benefits of SiC technology. SiC is a truly innovative and value-adding technology which helps to support the global climate saving trend and to drive new markets such as solar energy and high-efficiency lighting systems. It clearly underlines Infineon's leadership in and commitment to the power management market.

And there is still more to come from Infineon. The recession has been a good time for companies to re-evaluate their designs and there has been much design activity below the surface. The huge uptake of Infineon’s third generation of its thinQ!™ SiC Schottky diodes also builds on the success of its CoolMOS technology. Customers have shown a high level of interest in the adoption of the company’s SiC offering with double-digit growth in orders achieved.

Infineon’s third generation thinQ! SiC Schottky diodes are available in 600 Volts (3, 4, 5, 6, 8, 9, 10, and 12A), in both TO-220 and DPAK packages, and in 1200 V products (2, 5, 8, 10, and 15 A) in TO-220 package. In quantities of 10,000 pieces, third generation SiC Schottky diodes with a blocking voltage of 600 Volts (3A) are priced at Euro 0.45 per unit. The 4A version is priced at Euro 0.60 per unit, the 8A version at Euro 1.20 per unit.

Further information on Infineon’s SiC Schottky diodes is available at www.infineon.com/sic

Further details on Infineon’s power semiconductor product portfolio is available at www.infineon.com/powermanagementdiscretes

www.infineon.com