www.DataSheet4U.com ISDN U-BUS Input/Output Transformer TEW5714 TEW5714 is designed to interface with the subscribers premises (NT) and the 2- wire line side of the Central Office Equipment (LT) in the ISDN Network. TEW5714 meet the electrical requirements for the MOTOROLA MC145572 device. Applications: Low profile construction. Up to 50 mA line current. TEW5714 meets the requirements of BS6301 for reinforced insulation, clearance and creepage distances between.