6 Test Setup and Procedures

There were five input supplies used to power the TPS7H4104-SEP which provided V_IN and EN for each channel. The V_IN for the device was provided via Ch. 3 of an N6705C power module and ranged from 3.3 to 5V for SET and 6.5 to 7V for SEL and SEB/SEGR. Each channel's EN was provided from channels 1 and 2 of two distinct E36311A power supplies and were forced to either 0V for SEB Off or 5V for SET and other DSEE testing.

The primary signal monitored on the EVM was the V_OUT of each channel using four distinct NI PXIe-5172 scope cards which were set to trigger on a 3% window based on the nominal value of the channel's V_OUT. All SEB On, SEL, and SET testing used these conditions with only the SEB Off testing having different conditions. The conditions for SEB Off were a positive edge trigger at 0.5V which checks to see if the device ever incorrectly turned on while it was disabled.

To load each channel of the device a Chroma 63600 E-load was attached to a channel in Constant Resistance (CR) mode to achieve either a 1.5A or 3A load. In some cases, a 0.39Ω or a 0.56Ω power resistor was used to achieve a 3A load or power resistors were put in series to achieve a 1.5A load.

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 via 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 TPS7H4104-SEP.

All boards used for SEE testing were fully checked for functionality. Dry runs were also performed to ensure that the test system was stable under all bias and load conditions prior to being taken to the radiation test facilities. During the heavy-ion testing, the LabVIEW control program powered up the TPS7H4104-SEP device and set the 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, 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 when operating within the SOA.

Figure 6-1 Block Diagram of the SEE Test Setup for the TPS7H4104-SEP