The single event and total dose hardened IS-1825ASRH and ISL71823ASRH pulse width modulators are designed to be used in high frequency, switching power supplies in either voltage or current-mode configurations. Both designs include a precision voltage reference, a low power start-up circuit, a high frequency oscillator, a wide-band error amplifier and a fast current-limit comparator. The IS-1825ASRH features dual, alternating outputs operating from zero to less than 50% duty-cycle, while the ISL71823ASRH features dual, in-phase outputs operating from zero to less than 100% duty cycle. Constructed with the Intersil Rad-hard Silicon Gate (RSG) dielectrically isolated BiCMOS process, these devices are immune to single event latch-up and have been specifically designed to provide a high level of immunity to single event transients. All specified parameters are guaranteed and tested for 300krad(Si) total dose performance.