The HS-303ARH and HS-303BRH analog switches are monolithic devices fabricated using Intersil's dielectrically isolated Radiation Hardened Silicon Gate (RSG) process technology to insure latch-up free operation. They are pinout compatible and functionally equivalent to the HS-303RH, but offer improved 300kRAD(Si) total dose capability. These switches offers low-resistance switching performance for analog voltages up to the supply rails. "ON" resistance is low and stays reasonably constant over the full range of operating voltage and current. "ON" resistance also stays reasonably constant when exposed to radiation. Break-before-make switching is controlled by 5V digital inputs. The HS-303ARH should be operated with nominal 15V supplies, while the HS-303BRH should be operated with nominal 12V supplies.