SN74HCS251/SN74HCS251-Q1 8-to-1 Multiplexers Texas Instruments SN74HCS251/SN74HCS251-Q1 8-to-1 Multiplexers with 3-State Outputs and Schmitt Trigger Inputs provide the full binary decoding to select 1-of-8 data sources. The TI SN74HCS251/SN74HCS251-Q1 Multiplexer features strobe-controlled complementary 3-state outputs.