20/12/2024 5:13 am
Topic starter
Notifications
Clear all
0
hi everyone,
I often hear about bypass capacitors being used to filter noise in circuits, but I’m a bit confused about how they actually work.
- Do they filter true AC signals, or are they mainly for high-frequency noise superimposed on DC (like ripple or switching noise)?
- Does the term "AC noise" refer to actual alternating current or just rapid fluctuations on a DC line?
1 Answer
0
23/12/2024 12:17 pm
Bypass capacitors are primarily used to filter high-frequency noise superimposed on a DC signal, such as ripple or switching noise, rather than filtering true AC signals.
These capacitors provide a low-impedance path for high-frequency noise to ground, effectively bypassing the noise away from sensitive components while leaving the DC signal largely unaffected due to their high impedance at low frequencies.
The term "AC noise" in this context does not refer to actual alternating current but rather to rapid fluctuations or high-frequency disturbances, such as switching transients or electromagnetic interference, that are superimposed on the DC voltage. Therefore, bypass capacitors are essential for maintaining stable DC power by eliminating unwanted high-frequency noise rather than filtering traditional sinusoidal AC signals.
