S/P impedance calculator
Uncommon impedance: find out the best approximation (v1.0)
The problem is that the impedance found by many electrical design programs are not commonly available. Generally speaking, manufacturers follow an octave-based grouping of impedance values for their commercialized resistors, capacitors, and inductors.
For instance, the most common series of values are E6 and E12, which represent a logarithmic splitting of one decade into 6 or 12 points,
E6 = 1.00 1.50 2.20 3.30 4.70 6.80
E12 = 1.00 1.20 1.50 1.80 2.20 2.70 3.30 3.90 4.70 5.60 6.80 8.20
E24 = 1.00 1.10 1.20 1.30 1.50 1.60 1.80 2.00 2.20 2.40 2.70 3.00 3.30 3.60 3.90 4.30
4.70 5.10 5.60 6.20 6.80 7.50 8.20 9.10
together with more complete series:
E48 = 1.00 1.05 1.10 1.15 1.21 1.27 1.33 1.40 1.47 1.54 1.62 1.69 1.78 1.87 1.96 2.05
2.15 2.26 2.37 2.49 2.61 2.74 2.87 3.01 3.16 3.32 3.48 3.65 3.83 4.02 4.22 4.42
4.64 4.87 5.11 5.36 5.62 5.90 6.19 6.49 6.81 7.15 7.50 7.87 8.25 8.66 9.09 9.53
E96 = 1.00 1.02 1.05 1.07 1.10 1.13 1.15 1.18 1.21 1.24 1.27 1.30 1.33 1.37 1.40 1.43
1.47 1.50 1.54 1.58 1.62 1.65 1.69 1.74 1.78 1.82 1.87 1.91 1.96 2.00 2.05 2.10
2.15 2.21 2.26 2.32 2.37 2.43 2.49 2.55 2.61 2.67 2.74 2.80 2.87 2.94 3.01 3.09
3.16 3.24 3.32 3.40 3.48 3.57 3.65 3.74 3.83 3.92 4.02 4.12 4.22 4.32 4.42 4.53
4.64 4.75 4.87 4.99 5.11 5.23 5.36 5.49 5.62 5.76 5.90 6.04 6.19 6.34 6.49 6.65
6.81 6.98 7.15 7.32 7.50 7.68 7.87 8.06 8.25 8.45 8.66 8.87 9.09 9.31 9.53 9.76
E192 = 1.00 1.01 1.02 1.04 1.05 1.06 1.07 1.09 1.10 1.11 1.13 1.14 1.15 1.17 1.18 1.20
1.21 1.23 1.24 1.26 1.27 1.29 1.30 1.32 1.33 1.35 1.37 1.38 1.40 1.42 1.43 1.45
1.47 1.49 1.50 1.52 1.54 1.56 1.58 1.60 1.62 1.64 1.65 1.67 1.69 1.72 1.74 1.76
1.78 1.80 1.82 1.84 1.87 1.89 1.91 1.93 1.96 1.98 2.00 2.03 2.05 2.08 2.10 2.13
2.15 2.18 2.21 2.23 2.26 2.29 2.32 2.34 2.37 2.40 2.43 2.46 2.49 2.52 2.55 2.58
2.61 2.64 2.67 2.71 2.74 2.77 2.80 2.84 2.87 2.91 2.94 2.98 3.01 3.05 3.09 3.12
3.16 3.20 3.24 3.28 3.32 3.36 3.40 3.44 3.48 3.52 3.57 3.61 3.65 3.70 3.74 3.79
3.83 3.88 3.92 3.97 4.02 4.07 4.12 4.17 4.22 4.27 4.32 4.37 4.42 4.48 4.53 4.59
4.64 4.70 4.75 4.81 4.87 4.93 4.99 5.05 5.11 5.17 5.23 5.30 5.36 5.42 5.49 5.56
5.62 5.69 5.76 5.83 5.90 5.97 6.04 6.12 6.19 6.26 6.34 6.42 6.49 6.57 6.65 6.73
6.81 6.90 6.98 7.06 7.15 7.23 7.32 7.41 7.50 7.59 7.68 7.77 7.87 7.96 8.06 8.16
8.25 8.35 8.45 8.56 8.66 8.76 8.87 8.98 9.09 9.19 9.31 9.42 9.53 9.65 9.76 9.88
The values above may be kΩ, nH, pF, or whatever, and you could find with difficulty any other type of value.
You will find below a small javascript-based interaction that will allow computing the best approximation of any value with a combination of either a series or a parallel of two EX impedances. Clearly, you must have a javascript-enabled web browser.
Find your combination
Select resistance (R), capacitance (C), or inductance (L), choose your series, enter the desired impedance value, press "calculate" and find the best approximation for your value.
Single component
Two components in series
Two components in parallel