A 4-bit ripple counter consists of flip-flops, which each have a propagation delay from clock to Q output of 15 ns. For the counter to recycle from 1111 to 0000, it takes a total of

The total time it takes for a 4-bit ripple counter to recycle from 1111 to 0000 is determined by the propagation delay of each flip-flop and the number of flip-flops in the counter.

Step 1: Understand the components A 4-bit ripple counter has 4 flip-flops. Each flip-flop has a propagation delay of 15 ns from clock to Q output.

Step 2: Calculate the total delay The total delay for the counter to recycle is the sum of the propagation delays of all the flip-flops. Since the counter is a 4-bit ripple counter, there are 4 flip-flops. Therefore, the total delay is 4 flip-flops * 15 ns/flip-flop = 60 ns.

So, it takes a total of 60 ns for the 4-bit ripple counter to recycle from 1111 to 0000.