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I am trying to get a better understanding of a good method for selecting ferrite beads from those available.

I have a CLC filter, with 1uF x7r ceramics for each C, L being a ferrite bead in a 0805 package. Following this a LDO regulator that may need to supply 80mA peak of regulated supply. There is a GSM antenna operating from 850-2100MHz a few cm away, which is why there is additional filtering at the input of the LDO which is a noise sensitive 3V rail (10uF + 1uF + 0.1uF + 47pF on output). Assuming we are not going to change this arrangement, could you make some suggestion on how to select this part?

I have read guidelines of specifying the load to be no more than 20% of its rated current. This is the ferrite bead I am currently looking at. How would this other ferrite bead compare, since it has a very different profile?

Comments? Thoughts? Suggestions?

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  • \$\begingroup\$ Schematic? What is your design goal? \$\endgroup\$ – winny Mar 19 at 22:33
  • \$\begingroup\$ Start with spectral PSRR and Load Reg step load specs then use s-parms for each part and verify performance or compute Zo to meet spec with spectral load and watch out for anti-resonance \$\endgroup\$ – Sunnyskyguy EE75 Mar 19 at 22:46
  • \$\begingroup\$ Do those capacitors share vias? They must NOT share vias. \$\endgroup\$ – analogsystemsrf Mar 20 at 4:11

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