GENERAL DESCRIPTION
Using internal termination, the LIU provides one bill of materials to operate in T1, E1, or J1 mode with minimum external components. EXAR’s LIU has patented high impedance circuits that allow the transmitter outputs and receiver inputs to be high impedance when experiencing a power failure or when the LIU is powered off. Key design features within the LIU optimize 1:1 or 1+1 redundancy and non-intrusive monitoring applications to ensure reliability without using relays. The on-chip clock synthesizer generates T1/E1/J1 clock rates from a selectable external clock frequency and outputs a clock reference of the line rate chosen. Additional features in