The TC74VHC27 is an advanced high speed CMOS 3-INPUT NOR
GATE 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 internal circuit is composed of 3 stages including a buffer output,
which provide high noise immunity and stable output.
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.

Features
 High speed: tpd = 4.1 ns (typ.) at VCC = 5 V
 Low power dissipation: ICC = 2 μA (max) at Ta = 25°C
 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 to 5.5 V
 Pin and function compatible with 74ALS27