6 Test Setup and Procedures

SEE testing was performed on a TPS7H2211-SP device mounted on a modified TPS7H2211EVM. The device power was provided by using the J3 (VIN-1) and J8 (GND) inputs with the N6765A precision power supply in a 4-wire configuration mounted on a N6705 rack. A Chroma E-Load (Electronic Load) in the Constant-Resistance (CR) modes were used to load the device to 3.5 A for the SEE testing campaign.

For the SEL, SEB, and SEGR, the device was powered up to the maximum recommended operating voltage of 14 V and loaded with the maximum load of 3.5 A. For the SEB/SEGR characterization, the device was tested under enabled and disabled modes. The device was disabled by using the TP 7 connecting EN to GND. The E-Load was connected even when the device was disabled to help differentiate if an SET momentarily activated the device under the heavy-ion irradiation. During the SEB and SEGR testing not a single input current event was observed when testing with ¹⁰⁹Ag.

For the SET characterization, the TPS7H2211-SEP was evaluated at input voltages ranging from 4.5 V (minimum recommended voltage) to 14 V (maximum recommended voltage), at I_LOAD of 3.5 A and under no-load conditions. The SET events were monitored using two National Instruments™ (NI) PXIe-5172 scope card. The first 5172 scope was used to monitored and trigger from V_OUT using a window trigger around ±3% from the nominal output voltage. The second 5172 scope was used to monitor and trigger from the Soft-Start (SS) at VIN-0.3 V, using a edge/positive trigger. Both scopes were mounted on a NI PXIe-1095 chassis. During SET testing, no V_OUT or SS transients or SS SETs were observed.

All 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-Express cable and a NI PXIe-8381 remote control module. Figure 6-1 shows a block diagram of the setup used for SEE testing of the TPS7H2211-SP. Table 6-1 shows the connections, limits, and compliance values used during the testing. During the SEL testing the device was heated to 125°C by using a Closed-Loop PID controlled heat gun (MISTRAL 6 System (120-V, 2400-W)). For the SEB and SEGR testing, the device was tested at room temperature ≈ 25°C. For SET testing, the device was tested at room temperature (no cooling or heating was applied to the DUT). Die temperature was verified using a FLIR IR-camera prior to the SEE test campaign.

All boards used for SEE testing were fully checked for functionality. Dry runs were also performed to make sure that the test system was stable under all bias and load conditions prior to being taken to the TAMU facility. During the heavy-ion testing, the LabVIEW control program powered up the TPS7H2211-SP device and set the external sourcing and monitoring functions of the external equipment. After functionality and stability had been 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 voltage exceeds the pre-defined ±3% window trigger, or when the PG signal changed from high to low (using a negative edge trigger), a data capture was initiated. In addition to monitoring the voltage levels of the two scopes, VIN current and the 5-V (beam on and off) signal from TAMU were monitored at all times. No sudden increases in current were observed (outside of normal fluctuations) on any of the test runs and indicated that no SEL events occurred during any of the tests.

Figure 6-1 Block Diagram of SEE Test Setup With the TPS7H2211-SP