Protection is an important topic for designs in factory automation and control. The reference design shows the superior protection capabilities of new 33-V protection devices (such as TVS3300) for factory automation and control. The Canadian Standards Association (CSA) Group has performed surge testing according to IEC 61000-4-5 on this reference design. The design has the required accuracy to measure the behavior of protection devices before and after EMI stress with respect to leakage and clamping voltage.