The OLH249 is designed especially for high-reliability applications that require optical isolation in radiation environments, such as gamma, neutron, and proton radiation with high current transfer ratio (CTR) and low saturation VCE. Each optocoupler consists of an LED and N-P-N silicon phototransistor electrically isolated, but optically coupled inside a hermetic TO-5 package. Electrical parameters are similar to the JEDEC registered 4N49 optocoupler, but have much better CTR degradation characteristics due to radiation exposure. The OLH249 has 100 percent high-reliability screened parts available. Contact us for more details.