Specifications

Figure 1-14. Equivalent circuit models of (a) a capacitor and (b) an inductor
Note: Generally, the following criteria can be used to roughly discriminate between low, middle,
and high impedances (Figure 1-15.) The medium Z range may be covered with an extension of
either the low Z or high Z range. These criteria differ somewhat, depending on the frequency
and component type.
Figure 1-15. High and low impedance criteria
In the frequency region where the primary capacitance or inductance of a component exhibits
almost a flat frequency response, either a series or parallel equivalent circuit can be applied as a
suitable model to express the real impedance characteristic. Practically, the simplest series and par-
allel models are effective in most cases when representing characteristics of general capacitor,
inductor, and resistor components.
1 k
100
k
Low Z Medium Z
High Z
Series
Parallel
C
Ls
R
s
Rp (G)
Cp
L
R
s
Rp (G)
(a) Capacitor
(b) Inductor
Rp
R
s
|Z|
Frequency
1
C
Series (Low |Z|)Parallel (High |Z|
)
Low Z
High Z
Log f
Log |Z|
R
s
L
|Z|
Frequency
Series (Low |Z|) Parallel ( High
|Z|)
R
p
Low Z
High Z
Log f
Log |Z
|
C
Rp (G)
Cp-Rp
C
Rs
Cs-Rs
L
R
s
Ls-Rs
L
Rp
(G)
Lp-Rp
1-9