Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
I found attached schematics image which has red cycle that has bulk capacitor series with 1 ohm resistor . Can I know the reason series resistor hare as well as the capacitor does not mention the polarities
We are using capacitor with series resistors in some cases to increase the ESR intentionally, e.g. with a ceramic capacitor as bypass capacitor for voltage regulators that require the ESR for stability. Also to reduce the Q of LC low pass filters. In this place, the series resistor doesn't seem to make sense.
This capacitor+resistor in parallel with another capacitor configuration is used to dampen inductive resonance in power supplies due to the interaction of parasitic inductances with bypass capacitors.
If you want to read more about it, Google the title of this article: “Bypass or decouple your way to power supply noise reduction”. EDN and EEtimes both have the same article I’m referring to.
I also believe that this may be used protect from surge current because at the beginning of the capacitor consume high current and result is low voltage at the output, then regulator try to increase output violate by reference with feedback
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.