The MC10H158 is a quad two channel multiplexer with common input select. A "high" level select enables input D00, D10, D20 and D30 and a "low" level select enables input D01, D11, D21 and D31. This MECL 10HTM part is a functional/pinout duplication of the standard MECL 10KTM family part, with 100% improvement in propagation delay and no increase in power-supply current.