I'm looking for values of parasitics for SMD thick thilm resistors (the cheap and readily available). Values of the following model

enter image description here

Closest I found is this application note from Vishay, but it is for thin film resistors, and it gives values but only up to 0603 sizes. I'm looking for data for even bigger, up to 1206, but I'm not finding anything.

I'm interested in the model parameters to evaluate the impact of the parasitics on current design, and have a bound on the upper size we can handle. Any bound on maximum frequency for each size is also useful.

  • \$\begingroup\$ Stare at thousands of ceramic capacitor impedance curves in in Murata SimSurfer of different capacitances and voltage ratings in the same package. \$\endgroup\$
    – DKNguyen
    Jan 3 at 1:30
  • \$\begingroup\$ @DKNguyen Isn't it fair to say though that thick film resistors are simpler geometrically than caps, and therefore more similar from one brand to the next? \$\endgroup\$
    – Drew
    Jan 3 at 4:34
  • \$\begingroup\$ Oh, I misread it as capacitors. But I would still just look up a bunch of resistors, but impedance curves are a lot more difficult for those I imagine. \$\endgroup\$
    – DKNguyen
    Jan 3 at 4:40
  • \$\begingroup\$ Your best bet is to get access to a network analyzer covering the frequency range you're interested in, and a suitable test fixture, and measure the response of samples of the parts you are considering purchasing. \$\endgroup\$
    – The Photon
    Jan 3 at 6:19
  • \$\begingroup\$ You can get C roughly from the gap between the footprint pads and L from the loop from one footprint pad through the top of the package to the other pad. \$\endgroup\$
    – tobalt
    Jan 3 at 7:24


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.