STMicroelectronics (ST) and Velox Semiconductor have jointly introduced GaN (Gallium nitride) Schottky diodes, with a long-term goal of establishing both companies as dual-source suppliers of the devices. GaN-based diodes will enable the design and production of more efficient and lower-cost switch mode power supplies (SMPS).
ST and Velox offer complementary skills that the two companies believe will accelerate the development of the critical technologies and increasing the quantity and quality of product offerings available. Velox has developed 600-V GaN Schottky diodes and the diodes are in the final stages of development before transition to production. ST will help complete the development, perform product qualification, and will market and distribute the diodes.
In the first phase of the agreement, ST intends to test and qualify all the devices, and use its worldwide distribution system to market and distribute GaN Schottky diodes under the Velox brand name. In the second phase, Velox and ST expect to be full dual sources. Velox is licensing its production technology for the devices to ST to enable second-source manufacturing; both companies are working together to synchronize manufacturing and quality systems. These synchronization efforts may delay the start of the production originally planned by Velox, though the resulting delay will ensure an agile and consistent supply of GaN devices.
GaN is a wide bandgap semiconductor material, currently used typically in optoelectronic applications, and in high-power and high-frequency devices. In SMPS applications it enables the implementation of higher frequency power-factor correction circuits, which offer benefits in efficiency, product size, low noise, smaller heatsink requirements, and higher yield.
The use of a GaN device provides many advantages for the user, including reduced switching losses in both the diode and the MOSFET, elimination of active snubber components due to there being no voltage overshoot at turn-off, increased efficiency, and improved temperature performance.
The reduction in switching losses in GaN devices can be applied in a number of ways to optimize the user’s circuit design; by increasing efficiency, reducing heatsink requirements, or reducing the current rating of the transistor. The operating frequency can be increased to allow the use of smaller passive components, or to achieve acoustic requirements. The absence of high-frequency oscillation at turn-off reduces RFI filter requirements.