I’m using the Capacitive Multi-Touch Adapter schematic as a reference for a board I’m doing; and on Rev 1.1 it shows inductors L2-L5 as 220R@100Mhz.
What does 220R mean? Shouldn’t this be specificied in nH or uH? Is there an exact part# I can use to reference?
Thank you,
Erik
Hello Erik,
Components L2 - L5 are Ferrite beads, they are used to suppress or filter the amount of high frequency electromagnetic interference (EMI) noise found in electronic circuits.
They produce reactance (reactive impedance) that impedes the flow of higher frequency signals (commonly specified at 100 MHz by manufacturer).
Following is the link from Mouser Electronics (220R, 2A, 0603 size):
http://www.mouser.in/Passive-Components/EMI-RFI-Components/EMI-Filter-Beads-Chips-Arrays/_/N-bw7paZscv7Zlls6?P=1z0wqpiZ1z0wqgnZ1z0z7ymZ1yzvlkx&Keyword=ferrite+bead&Ns=Pricing|0&FS=True
Regards,
Satyan
