difference between bypass and decoupling capacitors

bypass capacitor chassis ground

difference between bypass and decoupling capacitors
please provide ur comments on this

vij

bulk bypass decouple

They are two different names for the same thing: bypass or decupling capacitor.
Regards,
IanP

bypass decoupling capacitor difference

but generally i have seen bypass capacitors are used in series
and decoupling capacitors aare used in parallel
are u agreee with this

vij

No, that is not true. Bypass/decoupling capacitors are always in parallel with supply rails..
Here you can find disription and details on how to select bypass/decoupling capacitors..
https://www.altera.com/support/devices/power/integrity/pow-integrity.html
Regards,
IanP

Decoupling capacitor, this name is used for those capacitors which suitably decouple the power lines and pins of the respective ICs. Whereas a bypass capacitor or a bulk capacitor is mainly for restricting the noise from entering into the pcb system. Usually bypass capacitors are used near the power supplies and the power supply pins of the connectors i.e. mainly at the power entry points of the pcb system. Any glitch or noise appearing on the power line is immediately bypassed into the chassis ground and thus prevented from entering into the system. Hence the name bypass capacitor.

Coming to decoupling capacitors, they are usually polarized and mainly act as charge buckets, thus, maintaining the potential near the respective power pins of the components and prevent the potential from dropping down below the supply threshold whenever the component(s) switches at considerable speeds or whenever there is simultaneous switching happening on the board, which calls in for extra demand of power.

Ultimately, its the term bypass cap is used for those capacitors which are used for filtering out the noise and preventing them from entering into the system and decap is used for those capacitors which act as charge buckets...bottom line is..they are all capacitors .

Decoupling Capcacitors are used for blocking DC/low freq signals, in multi-stage systems.

Bypass capacitors are used for reducing the negative feedback in caused by varrying signals.

I think bypass capacitor is used for signal.

and decouple capacitor is used for power supply.

Their function are same, both are used to

bypass high frequency.

best regards

vij said:

difference between bypass and decoupling capacitors
please provide ur comments on this

vij

Click to expand...