Initially, fully configurable transceivers presented king-pin devices in industrial networking. However, customers prefer simpler devices at lower cost. Hence, fixed-port devices that still support dual protocols but also enable operation down to 3.15 V are available in space-saving packages such as the 6 mm x 6 mm QFN. By providing both fixed and configurable dual protocol transceivers, Renesas can maintain its higher pricing for configurable devices, while offering attractive cost savings on fixed-port transceivers. Members of the fixed dual port transceivers family are the ISL33334, ISL33354, ISL33337, and ISL33357. Note that the fourth digit represents the nominal supply voltage (3 = 3.3 V, 5 = 5.0 V), while the fifth digit indicates the transceiver package (4 = SSOP-28, 7 = QFN-40).