The QS3251 is a high-speed CMOS TTL-compatible 8:1 multiplexer/demultiplexer that has 3-state outputs. The QS3251 is a function and pinout-compatible version of the 74F251, 74FCT251, and the 74ALS/AS/LS251 8:1 multiplexers. The low ON-resistance of the QS3251 allows inputs to be connected to outputs without adding propagation delay and without generating additional ground bounce noise. Mux/Demux devices provide an order of magnitude faster speed than equivalent logic devices. The QS3251 is characterized for operation at -40 °C to +85 °C.