Difficulty: Easy
Correct Answer: By connecting a radio-frequency capacitor from Vcc to ground.
Explanation:
Introduction / Context:
Totem-pole outputs momentarily source significant current during transitions, causing supply transients that can introduce noise, jitter, or logic errors. Proper decoupling at each IC suppresses these spikes and maintains local supply integrity.
Given Data / Assumptions:
Concept / Approach:
Place a small RF bypass capacitor (e.g., 0.01–0.1 µF ceramic) as close as possible between Vcc and ground at each IC. This provides a low-impedance path for high-frequency currents, preventing them from propagating along the power rails. Larger bulk capacitors support lower-frequency load changes; both are often used together.
Step-by-Step Solution:
Verification / Alternative check:
Oscilloscope measurements with and without local decoupling clearly show reduced supply ringing and cleaner edges.
Why Other Options Are Wrong:
Common Pitfalls:
Using long traces to decouplers; parasitic inductance defeats high-frequency bypass action.
Final Answer:
By connecting a radio-frequency capacitor from Vcc to ground.
Discussion & Comments