The 74VHC139FT is an advanced high speed CMOS 2 to 4 LINE DECODER/DEMULTIPLEXER fabricated with silicon gate C2MOS technology. It achieves the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. The active low enable input can be used for gating or it can be used as a data input for demultiplexing applications. When the enable input is held High, all four outputs are fixed at a high logic level independent of the other inputs. An input protection circuit ensures that 0 to 5.5 V can be applied to the input pins without regard to the supply voltage. This device can be used to interface 5 V to 3 V systems and two supply systems such as battery back up. This circuit prevents device destruction due to mismatched supply and input voltages.

Wide operating temperature: Topr = -40 to 125 
High speed: Propagation delay time = 3.8 ns (typ.) at VCC = 5.0 V
Low power dissipation: ICC = 2.0 μA (max) at Ta = 25 
High noise immunity: VNIH = VNIL = 28 % VCC (min)
Power-down protection is provided on all inputs.
Balanced propagation delays: tPLH ≈ tPHL
Wide operating voltage range: VCC(opr) = 2.0 to 5.5 V