EVL6563S-200ZRC STMicroelectronics, EVL6563S-200ZRC Datasheet - Page 8

• 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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Zero-ripple current phenomenon: theory
Equation 6
Equation 5
zero-ripple current phenomenon to occur, but unfortunately its physical nature is not shown.
To provide some physical insight, let us consider the a = n coupled inductor model (n is the
physical turn ratio N
Figure 6.
Proceeding with the same technique, in order for the ripple current i
voltage across the secondary leakage L l
L l
primary side of the ideal transformer v'(t) is given by the ratio of the inductive divider made
up of the primary leakage inductance L l
applied to the left-hand side of L l
secondary side of the coupled inductor if the following condition is fulfilled:
Equation 7
which is equivalent to
Equation 7
occurs when the turn ratio exactly compensates for the primary winding leakage flux, so that
the primary winding induces, by transformer effect, a voltage identical to its own excitation
voltage on the secondary winding; and so, if this is externally excited by the same voltage,
no ripple current flows through it.
The extensions of this interpretation to the case of zero-ripple primary current (just reflect
the magnetizing inductance L
voltages (α ≠ 1) are obvious.
2
must be equal to one another. On the other hand, if i2(t)=0 the voltage impressed on the
provides the desired physical interpretation of the zero-ripple current condition: it
and
Coupled inductor a = n model under zero-ripple current conditions
6
are noteworthy because of their concision in expressing the conditions for
2
/N
Equation 5
L
1
l
) excited by equal terminal voltages v(t), shown in
1
L
+
M
L
M
M
Doc ID 17273 Rev 1
n
to the secondary side) and to that of proportional excitation
2
v
and
(t)
is equal to nv '(t). Then, there is zero-ripple current on the
k
=
n
e
v
6
(t)
, as can be easily shown, considering that L
=
1
2
and the magnetizing inductance L
k
must be zero, that is, the voltages on either side of
⇒
L
L
2
1
=
L
l
L
1
M
L
1
+
M
=
L
M
1
n
=
L
L
M
1
n
=
2
1
(t) to be zero, the
Figure 6
M
; the voltage
.
M
AN3180
= M/n.