ABB Semiconductors offers a wide range of fast recovery diodes, standard recovery diodes and welding diodes.
Fast diodes are companion devices to switches in DC to AC conversion. Every switch (GTO, IGCT or IGBT) requires a complementary diode (e.g. for "free-wheeling" reactive power) in order to enable operation of the DC-AC conversion system with inductive loads. Fast diodes are optimized to accept high dynamic stress (fast transition from conducting to blocking state). However, they generally have higher conduction losses than rectifier diodes. For every switch family (GTO, IGCT and IGBT), we offer fast diodes that are optimized for the switch application.
Standard recovery diodes (rectifier diodes), are generally used for conversion of AC (alternating current) to DC (direct current). Rectifier diodes are split into two sub-classes: Normal recovery diodes and avalanche diodes. Normal recovery diodes are optimized with respect to low conduction losses and are able to handle very large currents. Avalanche diodes are self protected against transient over-voltages.
Welding diodes are rectifier diodes specially designed for medium and high frequency welding equipment and optimized for high current rectifiers. Their characteristics are the low forward voltage drop, excellent surge current ratings, very low thermal resistance and high operating temperature up to 190 °C. ABB follows new trends and the requirments of the automotive industry, such as the trend to higher frequencies of up to 10 kHz. To meet these demands, we are introducing a new group of high frequency welding diodes with high current capability combined with excellent reverse recovery characteristics. These new features enable operation with high efficiency at frequencies around 10 kHz. Thanks to this innovation, a welding transformer can be smaller and lighter. Thus, as part of a welding gun, it enables the robot arm to move easier and faster. New high frequency WDs are available in standard or housing-less (HL) versions.