A 23-ps/2.1-mW ECL gate with an AC-coupled active pull-down emitter-follower stage

An emitter-coupled logic (ECL) gate with an AC-coupled active pull-down emitter-follower stage that gives high speed at lower power is described. Significant reduction of the speed-power product can be achieved over the conventional ECL gate. The speed/power advantages of the circuit have been demonstrated in a double-poly, trench-isolated, self-aligned bipolar process with 0.8- mu m (mask) emitter width. Unloaded gate delays of 21 ps at 4.1 mW/gate, 23 ps at 2.1 mW/gate, and 35 ps at 1.1 mW/gate have been measured. >