Emitter-coupler or current-mode logic integrated interface circuit - can provide either type of interface according to whether control input terminal is earthed or left open

摘要

Input signals (I1, I2) are applied to a differential amplifier stage comprising two transistors (T1, T2) emitter-coupled to a current source (Io). An open collector of the CML interface and an open emitter of the ECL interface are each connected to a common output (Q1, Q2). The choice of interface is made by the control input connection (Mecl) which for CML interface activation is left open and for an ECL interface is earthed. A current source control circuit (1) reduces losses. USE/ADVANTAGE - In digital transmission systems using 100 Mbit/s transmission rates. Additional external components are avoided and circuit is easily adaptable to any application.