Description
The HD74HCT688 compares bit for bit two 8-bit words and indicate whether or not they are equal. The P=Q 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.

FEATUREs
• LSTTL Output Logic Level Compatibility as well as CMOS Output Compatibility
• High Speed Operation: tpd (Data to P=Q) = 18 ns typ (CL = 50 pF)
• High Output Current: Fanout of 10 LSTTL Loads
• Wide Operating Voltage: VCC = 4.5 to 5.5 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)