MC1668L Dual Clocked Latch Dip IC 16 Pin

From the shop's description

General Features: Gate Switching Speeds of 1.0 ns typical the capability of Driving terminated lines with impedance as low as 50 Ohms Flip-Flop Toggle Rate Greater than 500Mhz Operation with unused inputs left open Multilayer metalization for economy New Package with Improved electrical and thermal characteristics Compatibility with MECL 10,000 series Counting speeds above 1 GHz MC1668 Datasheet