Heavy ions were used to irradiate the devices. A nominal flux of 1 × 10⁵ ions / s-cm² was used for SEL characterization, at 125°C die temperature. Nominal fluxes of 1 × 10⁵ ions / s-cm² to 5 × 10⁵ ions / s-cm² were used for SET characterization, at ambient temperature.

For SEE characterization, the OPA4H014-SEP was biased with split supplies. On all four channels, the inverting input was connected to the output as shown in Figure 4-3. Both a buffer condition and positive-gain condition were tested. Jumpers were used to modify the load resistance and change from G = 1 to G = 10. The default positions are shown.

Input and supply voltages were provided by SMU PXI cards, connected with banana cables. A common input signal was applied to all channels. Figure 4-4 shows the decoupling capacitance scheme used on each board. Current was monitored over time for both V+ and V-. For SET testing, the device outputs were monitored using oscilloscope PXI cards, connected with BNC cables. 100Ω of series isolation resistance was used on each output channel to drive the cable capacitance.

An example of a decapped unit mounted on a characterization board is shown in Figure 4-5. The back side of the characterization board is shown in Figure 4-6. Note that despite silkscreen marking, 2kΩ resistors were used instead of 50Ω.