Cree Application Note: SiC Power Schottky Diodes in Power Factor Correction Circuits

Electronic systems operating in the 600to 1200-V range currently utilize silicon (Si) PiN diodes, which tend to store large amounts of minority carrier charge in the forward-biased state. The stored charge has to be removed by carrier recombination before the diode can be turned off. This causes long storage and turn-off times. Power devices made with silicon carbide (SiC) show great performance advantages as compared to those made with other semiconductors. The prime benefits of the SiC Schottky barrier diode (SBD) lie in its ability to switch fast (<50 ns), with almost zero reverse-recovery charge, even at high junction temperature operation. The comparable silicon PiN diodes (Si SBDs are not viable in the 600 V range because of their large on-state voltage drops) have a reverse-recovery charge of 100-500 nC and take at least 100 ns to turn-off. This places a tremendous burden on other switching elements in the system in terms of the required forward safe operating area and the switching losses incurred.