Explain the Propagation Delay characteristics for digital IC's.

Ans:

Propagation Delay: - The speed of a digital IC operation is given in terms of propagation delay time. The delay time is measured among the 50 percent voltage levels of input and output wave forms. Here two delay times are given.

a) t_phl = While the output goes from HIGH state to LOW state.

b) t_plh = While the output goes from Low state to HIGH state.

The propagation delay time of the logic gate is obtained as the average of these two delay times.