74HC521 pdf datasheet

MM54HC521/MM74HC521
8-Bit Magnitude Comparator (Equality Detector)
General Description
This equality detector utilizes advanced silicon-gate CMOS
technology to compare bit for bit two 8-bit words and indicates
whether or not they are equal. The PeQ output indicates
equality when it is low. A single active low enable is
provided to facilitate cascading of several packages and enable
comparison of words greater than 8 bits.
This device is useful in memory block decoding applications,
where memory block enable signals must be generated
from computer address information.
The comparator's output can drive 10 low power Schottky
equivalent loads. This comparator is functionally and pin
compatible to the 54LS688/74LS688 and the 54HC688/
74HC688. All inputs are protected from damage due to static
discharge by diodes to VCC and ground.
Features
Y Typical propagation delay: 20 ns
Y Wide power supply range: 2±6V
Y Low quiescent current: 80 mA (74 Series)
Y Large output current: 4 mA (74 Series)
Y Identical to 'HC688