Given the damping factor is 1.848 and R2 = 6.8k. determine the value of R1 to obtain a 4-pole Butterworth response.

a) 1.0kΩ
b) 44.7kΩ
c) 12.6kΩ
d) 3.7kΩ

1 answer

The formula for the damping factor of a 4-pole Butterworth filter is:

ζ = 1 / (2^(1/2))

Setting this equal to R2 / (2*R1) and solving for R1:

R1 = R2 / (2 * ζ)

R1 = 6.8kΩ / (2 * (1 / (2^(1/2))))

R1 = 6.8kΩ * (2^(1/2))

R1 = 9.6kΩ

The closest answer choice is c) 12.6kΩ.