Topic: Electronics Engineering
A certain JK FF has $t_{pd}=12$ ns. The largest MOD counter that can be constructed from such FFs and still operate to 10 MHz is
- A. 16
- B. 256
- C. 8
- D. 128
Answer: B. 256
Explanation: $f_{max}=\frac{1}{nt_{pd}}$ Where, $n=$ number of FFs, $t_{pd}=$ propagation delay of FF, $f_{max}=$ maximum operating frequency.
$10\times10^{6}=\frac{1}{(n\times12)ns}$
$n=\frac{1}{10\times12\times10^{6}\times10^{-9}}=8.33\simeq8.$
Mod-counter $=2^{n}=256$