Power integrations InnoSwitch3, Application Note, Page: 10 / 36

Rev. A 10/18
10
Application Note AN-72
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Step 4 – Transformer Construction Parameters
Enter: CORE, AE, LE, AL, VE, BOBBIN, AW, BW, MARGIN
Choose Core and Bobbin based on maximum output power.
Core Type, CORE
By default, if the core type cell is left empty, the spreadsheet will
select the smallest commonly available core suitable for the
continuous (average) output power specified. Different core types
61
TRANSFORMER CONSTRUCTION
PARAMETERS
62
CORE SELECTION
63 CORE RM6 Info RM6
The transformer windings may not fit: pick a
bigger core or bobbin and refer to the Transformer
Parameters tab for fit calculations
64 CORE CODE PC95RM06Z Core code
65 AE 37.00 mm^2 Core cross sectional area
66 LE 29.20 mm Core magnetic path length
67 AL 2150 nH/turns^2 Ungapped core effective inductance
68 VE 1090.0 mm^3 Core volume
69 BOBBIN B-RM06-V Bobbin
70 AW 15.52 mm^2 Window area of the bobbin
71 BW 6.20 mm Bobbin width
72 MARGIN 0.0 mm
Safety margin width (Half the primary to
secondary creepage distance)
73
74
PRIMARY WINDING
75 NPRIMARY 77 Primary turns
76 BPEAK 3125 Gauss Peak flux density
77 BMAX 2844 Gauss Maximum flux density
78 BAC 933 Gauss AC flux density
79 ALG 140 nH/turns^2 Typical gapped core effective inductance
80 LG 0.310 mm Core gap length
81 LAYERS_PRIMARY 4 4 Number of primary layers
82 AWG_PRIMARY 30 AWG Primary winding wire AWG
83 OD_PRIMARY_INSULATED 0.303 mm
Primary winding wire outer diameter with
insulation
84 OD_PRIMARY_BARE 0.255 mm
Primary winding wire outer diameter without
insulation
85 CMA_PRIMARY 248 Cmil/A Primary winding wire CMA
86
87
SECONDARY WINDING
88 NSECONDARY
6
6 Secondary turns
89 AWG_SECONDARY 19 AWG Secondary winding wire AWG
90 OD_SECONDARY_INSULATED 1.217 mm
Secondary winding wire outer diameter with
insulation
91 OD_SECONDARY_BARE 0.912 mm
Secondary winding wire outer diameter without
insulation
92 CMA_SECONDARY 216 Cmil/A Secondary winding wire CMA
93
94
BIAS WINDING
95 NBIAS 15 Bias turns
Figure 7. Transformer Core and Construction Variables Section of InnoSwitch3 PIXLs Spreadsheet.
and sizes from the drop-down list are available to choose from if a
user-preferred core is not available, the grey override cells (AE, LE,
AL, VE, AW & BW) can be used to enter the core and bobbin
parameters directly from the manufacturer’s data sheet.