Nov 30, 2009 #1 D devendra_devgupta Member level 3 Joined Apr 8, 2007 Messages 54 Helped 3 Reputation 6 Reaction score 0 Trophy points 1,286 Activity points 1,632 decoupling capacitor hi friends what should be the quality factor of a decoupling capacitor at 1MHz
Nov 30, 2009 #2 V vfone Advanced Member level 6 Joined Oct 10, 2001 Messages 5,710 Helped 1,616 Reputation 3,237 Reaction score 1,249 Trophy points 1,393 Activity points 36,270 Re: decoupling capacitor The reactance Xc of the decoupling capacitor should be less than 1 ohm at decoupling frequency. At resonant frequency (SRF) the reactance of the capacitor is minimum, but also the Q is minimum. To give an example: A decoupling capacitor with SRF =10MHz, Xc@10MHz = 0.5 ohms, Q@10MHz = 1, can have Q@1MHz = 100.
Re: decoupling capacitor The reactance Xc of the decoupling capacitor should be less than 1 ohm at decoupling frequency. At resonant frequency (SRF) the reactance of the capacitor is minimum, but also the Q is minimum. To give an example: A decoupling capacitor with SRF =10MHz, Xc@10MHz = 0.5 ohms, Q@10MHz = 1, can have Q@1MHz = 100.