ML4813IS View Datasheet(PDF) - Micro Linear Corporation
Part Name
Description
MFG CO.
'ML4813IS' PDF : 15 Pages View PDF
APPLICATIONS (Continued)
INDUCTOR INFORMATION
L3 is the flyback inductor and also provides the operating
power for the control circuitry. A gapped ferrite pot core
was chosen for this application for it's modest high
frequency losses with high ripple current operation. Some
possible choices are:
Manufadurer Part #
Total Gap
NP
Magnetics Inc. F43019
0.05"
32
Phillips
3019 PL00-3F3 0.05"
32
Phillips
3019 PA125-3C8 0.07"
38
The first 2 cores are sold ungapped and require the use of
a .025. spacer to gap the center leg to yield a total gap
length of 0.05". If an ungapped core is used, a "shorted
turn" should be employed as shown in Figure 14 to
prevent radiated EMI. The third core listed is sold with its
center ieg pre-gapped (0.07" total) so that the outside of
the core closes completely, providing shielding without a
shorted turn. NS should be 3 turns. All windings are
#24AWG wire.
Inductors L1 and L2 are constructed using a powdered
iron. This is a suitable material for these inductors since
the high frequency ripple currents (and resulting flux
excursions) are much less severe than for L3. The core
selected is a MicroMetals T68-26D with 80 turns or
#24AWG wire.
ML4813
SHORTED TURN
(COPPER FOIL)
0.25" SPACER
WINDINGS
Figure 14. EMI Shielding for Ungapped Cores
13
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