The OMR9604 is a radiation hardened, ultra low dropout adjustable linear regulator designed specifically for space applications. This product has been characterized to a total ionizing dose of 1 M Rad (Si) per MIL-STD-883, Method 1019, Condition A at both high and low dose rates under biased and unbiased conditions to account for ELDRS effects in bipolar devices. The ultra low dropout voltage of 0.4V @ 3A makes the part particularly useful for applications requiring low noise and higher efficiency.