To the unbalanced attenuator the output impedance is lower than the input impedance. The next formula are used to determine the components in this attenuator.
Formula 1
Where:
N is the attenuation factor (ratio between input/output voltage, currents or powers)
Zout is the output impedance ohm (Ω)
Zin is the input impedance in ohm (Ω)
Rp is the parallel resistance in ohm (Ω)
Formula 2
Rs1 = Zin x [ (N + 1) / (N – 1) ] - Rp
Where:
Rs1 is the series resistance in ohm (Ω)
Zin is the input impedance in ohm (Ω)
N is the attenuation factor
Rp is the parallel resistance in ohm (Ω)
Formula 3
Rs2 = Zout x [ (N + 1) / (N – 1) ] - Rp
Where:
Rs2 is the series resistance in ohm (Ω)
Zin is the input impedance in ohm (Ω)
N is the attenuation factor
Rp is the parallel resistance in Ω (Ω)
