6 Test Setup and Procedures

There were two input supplies used to power the TPS7H1121-SEP which provided V_IN and EN. The V_IN for the device was provided by Ch. 3 of an N6705C power module and ranged from 5V and 12V for SET to 14V for SEL and SEB/SEGR. EN was powered by Ch. 1 of an E36311A power supply and ranged from 0V for SEB Off to 5V for all other testing.

The instrument used to load the TPS7H1121-SEP was a Chroma 63600 E-Load that was used in Constant Resistance (CR) mode. The value of CR was adjusted depending on the type of test. For all DSEE testing with V_OUT = 13.3V, the CR value was set to achieve a max load of 2A. For the SEB testing during the V_OUT = 0.6V case, the CR value was set to achieve a load of 100mA as the CR value was set such that it does not heat the device too much to maintain a valid test case. For the SEL testing during the V_OUT = 0.6V case, the CR value was set to achieve a load that provided the correct amount of device heating to achieve a die temperature of 125°C; on the other hand, during the V_OUT = 13.3V case, the CR value was set to result in a load of 2A. For all SET testing, the CR value was set to achieve a nominal load of 1A.

The primary signal monitored on the EVM was V_OUT. This was monitored using a NI PXIe-5172 scope card that was set to trigger on a 3% window based on the nominal measured value of V_OUT. Secondary signals monitored include PG and SS. A second NI PXIe-5172 scope card was used to monitor PG on a negative edge trigger, set 50% below the nominal value of PG. A third NI PXIe-5172 scope card was used to monitor SS on a negative edge trigger, also set 50% below the nominal value of SS. During SEE testing, the output signals were monitored to maintain proper device functionality throughout the run. During SEB Off testing, all outputs were monitored on a positive edge trigger at 500mV to detect if the device incorrectly turned on while the device was disabled.

All other equipment was controlled and monitored using a custom-developed LabVIEW program (PXI-RadTest) running on a HP-Z4 desktop computer. The computer communicates with the PXI chassis through an MXI controller and NI PXIe-8381 remote control module.

Table 6-1 shows the connections, limits, and compliance values used during the testing. Figure 6-1 shows a block diagram of the setup used for SEE testing of the TPS7H1121-SEP.

All boards used for SEE testing were fully checked for functionality. Dry runs were also performed to maintain that the test system was stable under all bias and load conditions prior to being taken to the TAMU and KSEE facilities. During the heavy-ion testing, the LabVIEW control program powered up the TPS7H1121-SEP device and set the external sourcing and monitoring functions of the external equipment. After functionality and stability was confirmed, the beam shutter was opened to expose the device to the heavy-ion beam. The shutter remained open until the target fluence was achieved (determined by external detectors and counters). During irradiation, the NI scope cards continuously monitored the signals. When the output exceeded the pre-defined 3% window trigger or negative edge triggers, a data capture was initiated. No sudden increases in current were observed (outside of normal fluctuations) on any of the test runs and indicated that no SEL or SEB/SEGR events occurred during any of the tests.