Electronics and Communication Engineering - Digital Electronics - Discussion

Asynchronous circuits change state only through the inputs received by them. So, the operation is quite instantaneous since they don't have to wait for a clock pulse. They are limited by propagation delay of logic gates only.

But asynchronous circuits can transition into a wrong state due to incorrect arrival time of 2 inputs. This is called a race condition. Asynchronous circuits are quite difficult to design for a reliable operation. These are used primarily in high speed systems such as Signal Processing hardware.