The important characteristics of the digital ICs are:

• Fan out
• Power dissipation
• Propagation delay
• Noise margin
• Fan in
• Operating temperature
• Power supply requirements

Fan out:

The fan out specifies the number of standard loads that the output of the gate can drive without impairment of its normal operation.

Power dissipation:

It is the measure of power consumed by the gate when fully driven by all inputs.

Propagation delay:

It is the average transition delay time for the signal to propagate from input to output when the signals change in value.

It is expressed in ns.

Noise margin:

It is the maximum noise voltage added to an input signal of a digital circuit that does not cause an undesireable change in the circuit ouput.

It is expressed in volts.

Fan in:

Fan in is the number of inputs connected to the gate without any degradation in the voltage level.

Operating temperature:

All the gates or semiconductor devices are temperature sensitive in nature. The temperature in which the performance of the IC is effective is called as Operating temperature.