I have a CLLC circuit in which I am trying to find values of the inductors and capacitors. I know the circuit needs a gain of at least 10 dB at 50kHz and below 1 db at around 30-40KHz. This has to be true while varying the load. I have set up the circuit in ltspice where I am using the .step function to sweep through component values and am looking at the bode plots.

The problem is I have so many graphs on the screen that I cannot keep track of them all. In the 1000s. Is there a way I can only display the simulations which have over 10dB at 50KHz and under 1db below 30Khz? Basically I want to get rid of all the sims that don't meet my criteria. The circuit is way too complex for me to solve mathematical.

It's for a tank in a resonant tank charger. The load will vary from 4ohm to 12homs. The circuit is bidirectional and it would be helpful if the transfer function is similar in both directions. What other info should I post? I've been trying to make something similar to the circuit in this article. https://www.researchgate.net/profile/Ho_Sung_Kim3/publication/260496284_Design_Methodology_of_Bidirectional_CLLC_Resonant_Converter_for_High-Frequency_Isolation_of_DC_Distribution_Systems/links/00b7d5347ada7c098b000000/Design-Methodology-of-Bidirectional-CLLC-Resonant-Converter-for-High-Frequency-Isolation-of-DC-Distribution-Systems.pdf I understand basic laplace transforms but not enough to put this all together yet. I'm not overly interested in high efficiency, I know the load varies by a lot.

  • \$\begingroup\$ Maybe reduce the space you step over? You can right click on the plot and select the steps to plot there, but you can only select by paramter, not by plot outcome \$\endgroup\$ – PlasmaHH Apr 11 '18 at 21:04
  • \$\begingroup\$ 1st define Rs and R load (min) at gain = 10dB or Q=3 then I'll show you the easy way in 1 minute \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 11 '18 at 21:04
  • \$\begingroup\$ or Collector out and dont care load? \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 11 '18 at 21:10
  • \$\begingroup\$ or SMPS? switch source? \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 11 '18 at 21:23
  • \$\begingroup\$ It's easy if you give more info. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 11 '18 at 21:34

Why are you doing it the hard way? enter image description here enter image description here

or an easier way.

C1=3.3uF, L1=4uH, L2=2uH, C2=3.3uF, R=>1.5 Ohm
C1 in series with L1, L2 shunt, C2 series, R load shunt.

If using a voltage source Zs=0

Q > 11dB at 50kHz, < -30dB at 10kHz

Swap L1,L2 for higher Q.

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