74VHC  -  Series DataSheet
74VHC27  -  Triple 3-Input NOR Gate  -  Fairchild Semiconductor Corporation  -  NOR Gates

Features
■High speed: tPD=4.1ns (typ) at TA=25°C
■Low power dissipation: ICC=2μA (max) at TA=25°C
■High noise immunity: VNIH=VNIL=28% VCC(min.)
■Power down protection is provided on all inputs
■Low noise: VOLP=0.8V (max.)
■Pin and function compatible with 74HC27

General Description
The VHC27 is an advanced high speed CMOS 3-Input NOR Gate fabricated with silicon gate CMOS 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 buffer output, which provide high noise immunity and stable output. An input protection circuit insures that 0V to 7V can be applied to the input pins without regard to the supply voltage. This device can be used to interface 5V to 3V systems and two supply systems such as battery backup. This circuit prevents device destruction due to mismatched supply and input voltages.