The first step is to select the appropriate SSR component. The SSR uses a semiconductor FET to build the high-voltage ability switches with isolation barrier. Compared to a traditional relay or photo MOS, the SSR can support single or bidirectional ON and OFF control and a higher switching speed to enable less settling time. Additionally, SSR can support stand-alone switch control without a dedicated driver circuit or dedicated bias power for coil excitation. Table 2-1 summarizes the SSR components.

For an active single-switch architecture, select single channel SSR components. A higher standoff voltage is beneficial in high potential testing, and the higher avalanche current is very helpful for high potential testing. Therefore, TPSI2240T-Q1 is selected as the SSR component.