SLUK023A February 2019 – June 2024 UC1825B-SP
The UC1825B-SP LDR exposure is performed on biased and unbiased devices in a60Co gamma cell under a 10mrad(Si)/s exposure rate. The dose rate of the irradiator used in the exposure ranges from < 10mrad (Si)/s to a maximum of approximately 65rad(Si)/s, determined by the distance from the source. For the LDR (10mrad(Si)/s) exposure, the test box is positioned approximately 2m from the source. The exposure boards are housed in a lead-aluminum box (as specified in MIL-STD-883 TM 1019.9) to harden the gamma spectrum and minimize dose enhancement effects. The irradiator calibration is maintained by Logmire Laboratories using Thermoluminescence Dosimeters (TLDs) traceable to the National Institute of Standards and Technology (NIST) and the dosimetry is verified using TLDs prior to the radiation exposures. After exposure, the devices are returned to the TI Dallas facility for a full post radiation electrical evaluation using TI production Automated Test Equipment (ATE). ATE guard band test limits are set within SMD electrical limits to ensure a minimum Cpk and test error margin based on initial qualification and characterization data.