The UCC3813-x device family of high-speed, low-power integrated circuits contains all of the control and drive components required for off-line and DC-to-DC fixed-frequency current-mode switching power supplies with minimal parts count. These devices have the same pin configuration as the UC384x device family, and also offer the added features of internal full-cycle soft start and internal leading-edge blanking of the current-sense input. The UCC3813-x device family offers a variety of package options, temperature-range options, choice of maximum duty cycle, and choice of critical voltage levels. Devices with lower reference voltage such as the UCC3813-3 and UCC3813-5 fit best into battery operated systems, while the higher reference and the higher UVLO hysteresis of the UCC3813-2 device and UCC3813-4 device make these ideal choices for use in off-line power supplies. The UCC2813-x device series is specified for operation from –40°C to 85°C and the UCC3813-x device series is specified for operation from 0°C to 70°C.