Topic: Digital Electronics
A digital board has a unipolar square clock of 250 MHz. If the clock on the board at all places should have all the harmonic components which have more than 10% of DC value, the board has to be designed for at least
- A. 250 MHz
- B. 750 MHz
- C. 1250 MHz
- D. 2500 MHz
Answer: C. 1250 MHz
Explanation: Based on the official answer key, the correct option is (c). Detailed mathematical derivation is not provided in the reference, but representing the significant harmonics of a square wave often requires accounting for up to the 5th harmonic (i.e., $5 \times 250\text{ MHz} = 1250\text{ MHz}$) to accurately reconstruct the sharp edges of the clock.