MIL-PRF-19500/159R covers the performance requirements for 6.2 volts ± 5 percent, silicon, temperature compensated, voltage-reference diodes. Four levels of product assurance (JAN, JANTX, JANTXV, and JANS) are provided for each encapsulated device type as specified in MIL-PRF-19500, and two levels of product assurance are provided for each unencapsulated device type. Seven levels of radiation hardened assurance (total dose only) are provided for each encapsulated device type as specified in MIL-PRF-19500, and two levels of product assurance for quality levels JANTXV and JANS as specified in MIL-PRF-19500.