SM6T42CAY is an ultra-low capacitance, bidirectional transient suppressor diode from STMicroelectronics. It is designed for transient protection of sensitive electronics, specifically input/output lines, from destructive electrostatic discharge (ESD) and surge events. The device features an operating voltage range of 3.3V to 200V, a capacitance of 40 pF max between any two pins, and a peak pulse current rating of 400mA (8/20µs). It is available in a 6-Pin SC-59 package.