The 74VHC138FT is an advanced high speed CMOS 3-to-8 DECODER 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. When the device is enabled, 3 Binary Select inputs (A, B and C) determine which one of the outputs ( Y0 - Y7 ) will go low. When enable input G1 is held low or either G2A or G2B is held high, decoding function is inhibited and all outputs go high. G1, G2A , and G2B inputs are provided to ease cascade connection and for use as an address decoder for memory systems. 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
Low noise: V = 0.8 V (max)