Art of Electronics 3rd ed. Exercise 1.24
Design a band pass filter:
- first stage is high pass f₀=100Hz
- second stage is low pass f₀=10KHz
- input signal impedance: Rₛ=100Ω
1. What is the worst case output impedance of the filter
2. What is the minimum recommended load impedance
First stage:
R₁ >> Rₛ => R₁=1KΩ (10x rule of thumb)
f₀=1/2πR₁C₁ => C₁=1.59μF
Second stage:
R₂ >> R₁ => R₂ = 10KΩ (10x rule of thumb)
f₀=1/2πR₂C₂ => C₂=1.59nF
Worst case output impedance:
R₀ ≈ 10KΩ (10x rule of thumb)
Recomennded load impedance:
Rₗ = 100KΩ (10x rule of thumb)
