Cursed circuits #5: capacitance multiplier

2 comments

• inigyou 3 hours ago
  The last circuit, in steady state, behaves exactly as R2, but when the signal changes, the current through the capacitor is the derivative of the signal, reducing the amount by which the circuit is just R2.

  I speculate it acts like an inductor because that would be a logically silly thing for it to do but I'm not doing the math at 1am on my phone.

  I've always admired lcamtuf.

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  • femto 1 hour ago
    Yep. That topology is called a gyrator. Often used in IC's where it is hard to make an inductor.
• pclmulqdq 3 hours ago
  Wait until he hears about negative Miller capacitance.
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  • eulgro 19 minutes ago
    Yeah we can do really weird things with op amps, negative resistance and capacitance comes to mind.