High-frequency period calculation: What is the period (time for one cycle) of a 16 MHz sine wave?
-
A196 ns
-
B62.5 ns
-
C31.25 ns
-
D19.9 ns
-
E6.25 ns
Answer
Correct Answer: 62.5 ns
Explanation
Introduction:Converting between frequency and period is fundamental in signal processing, microcontroller timing, and communications. The period is the reciprocal of frequency: higher frequency means shorter period.
Given Data / Assumptions:
- Frequency f = 16 MHz = 16 * 10^6 Hz.
- Ideal single-tone sine wave.
- We need T in seconds (or nanoseconds).
Concept / Approach:
The relationship is T = 1 / f. After computing T in seconds, convert to nanoseconds by multiplying by 10^9. This quick conversion is widely used for clock signals in digital electronics.
Step-by-Step Solution:
Compute T = 1 / f = 1 / (16 * 10^6) s.T = 0.0625 * 10^-6 s.Convert to nanoseconds: T = 62.5 ns.Thus, one cycle of a 16 MHz signal lasts 62.5 ns.Verification / Alternative check:
Check by multiplication: 16 * 10^6 Hz * 62.5 * 10^-9 s = 1.0 (dimensionless), confirming consistency. Also, 8 MHz would be 125 ns; doubling frequency halves period, aligning with 16 MHz → 62.5 ns.
Why Other Options Are Wrong:
- 196 ns / 31.25 ns / 19.9 ns / 6.25 ns: Do not equal 1 / 16 MHz; some correspond to other frequencies (e.g., 32 MHz → 31.25 ns).
Common Pitfalls:
- Misplacing decimal points during unit conversion between microseconds and nanoseconds.
- Confusing MHz (10^6) with kHz (10^3) or GHz (10^9).
Final Answer:
62.5 ns