MIL-PRF-19500/548F, PERFORMANCE SPECIFICATION SHEET, COUPLER, OPTO ELECTRONIC, SEMICONDUCTOR DEVICE, SOLID STATE, TYPES 4N47, 4N48, 4N49, 4N47A, 4N48A, 4N49A, 4N47U, 4N48U, 4N49U, 4N47BU, 4N48BU, AND 4N49BU, JAN, JANTX, JANTXV, AND JANS (15 SEP 2005)., This specification covers the performance requirements for solid state optically coupled isolators in which a gallium aluminum arsenide diode light source is optically coupled to a silicon NPN phototransistor. Four levels of product assurance are provided for each type as specified in MIL-PRF-19500.