The SMA4F30AH with ESD Suppressors / TVS Diodes 400W, 35.3V, 5%, Unidirectional, TVS manufactured by Taiwan Semiconductor is a TVS diode designed to suppress electrostatic discharge (ESD) in electronic circuits. This device is unidirectional, meaning it will only allow current flow in one direction, and is rated at 400W power, 35.3V voltage, and 5% tolerance. Taiwan Semiconductor is a leading global supplier of semiconductor products to electronics companies.