EVL6563S-200ZRC STMicroelectronics, EVL6563S-200ZRC Datasheet - Page 30

• Manufacturer Part Number: EVL6563S-200ZRC
• Description: Power Management Modules & Development Tools Tranisition Mode PFC L6563S EVL Board
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of EVL6563S-200ZRC

• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Electrical equivalent circuit models of coupled inductors and transformers
Figure 23. Coupled inductors
The mutual inductance M cannot be assigned arbitrarily but must fulfill the inequality:
Equation 22
The case
generated by either winding is totally linked to the other. However, in real-world systems
there is always some flux linking one winding but not the other or not completely linking the
winding itself, e.g. because it “leaks” into the surrounding air; and so it is possible to write:
Equation 23
k, which lies in the range -1 k 1 is the so-called coupling coefficient and is a measure of the
degree of magnetic coupling between the windings. For simplicity, from now on winding
polarity is neglected and assume M>0 (and 0 k 1) always, the extension to the case M<0
being obvious.
It is possible to prove that k is the geometric mean of the portion k1 of flux generated by the
first winding that links the second one, and the portion k2 of flux generated by the second
winding that links the first one:
Equation 24
Note that, in general, k
another.
It is often useful to represent a system of coupled inductors with an equivalent circuit
including an ideal transformer, that is a circuit element with a transfer function v
for voltages and i
M =
L
1
2
L
'(t) / i
2
is that of perfectly coupled inductors, that is when the magnetic flux
1
1
'(t)= 1/a for currents. This equivalent circuit is shown in
≠ k
2
: fluxes do not necessarily link windings symmetrically one to
Doc ID 17273 Rev 1
M =
M ≤
k =
k
k
L
L
1
1
1
k
L
L
2
2
2
2
Figure 24
'(t) / v
AN3180
1
'(t)=a
.