EPR-31 Datasheet, PDF (25/36 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP-31 Multiple Output 180 W AC-DC Power

01-Feb-05
EPR-31 – Multi-Output, 180 W, PC Main Power Supply
TRANSFORMER CORE SELECTION
Core Type
Core
Bobbin
AE
LE
AL
BW
LG MAX
eer28l
EER28L
P/N:
EER28L_BOBBIN P/N:
0.814 cm^2
7.55 cm
2520 nH/T^2
21.8 mm
0.02 mm
R FACTOR
9%
M
3.0
L
0.80
NMAIN
TRANSFORMER DESIGN PARAMETERS
NP
45
9% %
mm
3
45
NB
6
NAUX1
4
VAUX1 ACTUAL
NIND1
11.63 Volts
0
VIND1 ACTUAL
0.00 Volts
PC40EER28L-Z
BEER-28L-1112CPH
Core Effective Cross Sectional Area
Core Effective Path Length
Ungapped Core Effective Inductance
Bobbin Physical Winding Width
Maximum actual gap when zero gap specified
Percentage of total PS losses lost in transformer
windings; default 10%
Transformer margin
Transformer primary layers
Main rounded turns
Primary rounded turns
Bias turns to maintain 8V minimum input voltage,
light load
Auxiliary rounded turns (DC stacked on Main
winding)
Approx. Aux output voltage with NAUX1 = 4 Turns
and DC stack
Independent rounded turns (separate winding)
Approximate Independent output voltage with
NIND1 = 0 turns
BM
BP
LP MIN
IMAG
OD_P
AWG_P
CURRENT WAVESHAPE PARAMETERS
IP
IPRMS
INDUCTOR OUTPUT PARAMETERS
LMAIN
WLMAIN
KDIMAIN
Maximum operating flux density at minimum
1816 Gauss switching frequency
Maximum peak flux density at minimum switching
2922 Gauss frequency
Minimum primary magnetizing inductance
3.419 mHenries (assumes LGMAX=20um)
Peak magnetizing current at minimum input
0.188 Amps voltage
0.33 mm
Primary wire outer diameter
Primary Wire Gauge (rounded to maximum AWG
28 AWG value)
3.079 Amps
1.727 Amps
Maximum peak primary current at maximum DC
Bus voltage
Maximum primary RMS current at minimum DC
Bus voltage
7.6 uHenries
3034 uJoules
0.150
Main / Auxiliary coupled output inductance
(referred to Main winding)
Main / Auxiliary coupled output inductor full-load
stored energy
Current ripple factor of combined Main and Aux1
outputs
LMAINMA
WLMAINMA
KDIMAINMA
LIND1
WLIND1
KDIIND1
12.3 uHenries
888 uJoules
0.150
0.0 uHenries
0.0 uJoules
0.000
Magamp output inductance
Magamp output inductor full-load stored energy
Current ripple factor for Magamp output
Independent output inductance
Independent output inductor full-load stored
energy
Current ripple factor for Independent output
SECONDARY OUTPUT PARAMETERS
ISMAINRMSLL
ISAUX1RMSLL
ISIND1RMSDLL
IDAVMAIN
17.36 Amps
4.23 Amps
0.00 Amps
14.6 Amps
Maximum transformer secondary RMS current (DC
Stack)
Maximum transformer secondary RMS current (DC
Stack)
Maximum transformer secondary RMS current
Maximum average current, Main rectifier (single
device rating)
Page 25 of 36
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