The SMA4S15AH with ESD Suppressors / TVS Diodes 400W, 17.7V, 5%, Unidirectional, TVS manufactured by Taiwan Semiconductor is a type of bidirectional transient voltage suppressor (TVS) with 400 Watt (W), 17.7 Volt (V), 5% tolerance, and unidirectional polarity built by Taiwan Semiconductor. It is outfitted with Electro Static Discharge (ESD) suppressors to protect the circuit against voltage spikes and sudden power changes. This component is designed for high-speed automotive, industrial, and consumer applications. It can also be used for surge and overvoltage protection, as well as voltage regulation, overcurrent protection, and radio frequency interference (RFI) suppression.