An eight stage ripple counter uses a flip-flop with propagation delay of 75 nanoseconds. The pulse width of the strobe is 50ns. The frequency of the input signal which can be used for proper operation of the counter is approximately (A) 1 MHz. (B) 500 MHz. (C) 2 MHz. (D) 4 MHz.

An eight stage ripple counter uses a flip-flop with propagation delay of 75 nanoseconds. The
pulse width of the strobe is 50ns. The frequency of the input signal which can be used for
proper operation of the counter is approximately
(A) 1 MHz. (B) 500 MHz.
(C) 2 MHz. (D) 4 MHz.
by

2 Answers

Answer :

(A) 1 MHz.
by

Answer :

Maximum time taken for all flip-flops to stabilize is 75ns x 8 + 50 = 650ns. Frequency of
operation must be less than 1/650ns = 1.5 MHz.
by

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