Vishay 600V FRED Pt Ultrafast Diodes The Vishay 600V FRED Pt Ultrafast Diodes feature TJ max of +175ºC, extremely low leakage current, and package availability (power packages, bare die, and bare wafers). The key applications for Vishay's 600V Fred Pt Ultrafast Diodes include DCM, CRM, and CCM PFC stage output rectification and anti-parallel diodes for adapters, UPS and air conditioning, and automotive.