The UES804 series of ultrafast high-efficiency rectifiers is specifically designed for operation in power switching circuits operating at frequencies of 20 kHz or higher. These devices have demonstrated capability in passing power-stress testing to 25 thousand cycles with full-rated forward current turned on and off without a heat sink. This forces case temperature increases of 75 ° C at which time the current is removed to simulate worst case applications. The switching times increase relatively little with temperature or at different currents.