kicad/pcb_calculator/attenuators/pi_formula.md

Pi attenuator

Zin desired input impedance in Ω
Zout desired output impedance
Zin = Zout

• a attenuation in dB
• L = 10^a/20 (the loss)
• A = (L + 1)/(L - 1)
  
  
• R2 = (L- 1)/2 * √ ( (Zin * Zout) / L)
• R1 = 1/( A/Zin - 1/R2 )
• R3 = 1/ (A/Zout - 1/R2 )