DER-94
LCD Monitor Internal Supply
September 12, 2005
7.6 Transformer Spreadsheet
ACDC_TOPGX_Rev1.2_052901 INPUT
Copyright Power Integrations Inc.
2001
INFO
INFO OUTPUT OUTPUT UNIT
TOP_GX_052901.xls:
TOPSwitch-GX
Continuous/Discontinuous
Flyback Transformer Design
Spreadsheet
ENTER APPLICATION VARIABLES
Customer
VACMIN
VACMAX
fL
VO
PO
n
Z
VB
tC
90
265
50
5
45
0.8
0.5
12
3
Volts
Volts
Hertz
Volts
Watts
Minimum AC Input Voltage
Maximum AC Input Voltage
AC Mains Frequency
Output Voltage
Output Power
Efficiency Estimate
Loss Allocation Factor
Bias Voltage
Volts
mSeconds Bridge Rectifier Conduction
Time Estimate
CIN
120
uFarads
Input Filter Capacitor
ENTER TOPSWITCH-GX VARIABLES
TOP-GX
TOP246
Universal 115 Doubled/230V
Chosen Device
TOP246
TOP246 Power
Out
Power
Out
90W
150W
KI
0.8
External Ilimit reduction
factor (KI=1.0 for default
ILIMIT, KI <1.0 for lower
ILIMIT)
ILIMITMIN
ILIMITMAX
1.944
2.376
1.944 Amps
2.376 Amps
Use 1% resistor in setting
external ILIMIT
Use 1% resistor in setting
external ILIMIT
Frequency - (F)=132kHz,
(H)=66kHz
fS
H
Half (H) frequency option -
66kHz
65000
6.50E+04 6.50E+04 Hertz
TOPSwitch-GX Switching
Frequency: Choose between
132 kHz and 66 kHz
TOPSwitch-GX Minimum
Switching Frequency
TOPSwitch-GX Maximum
Switching Frequency
Reflected Output Voltage
TOPSwitch on-state Drain to
Source Voltage
fSmin
6.15E+04 6.15E+04 Hertz
7.05E+04 7.05E+04 Hertz
fSmax
VOR
VDS
90
10
Volts
Volts
VD
0.5
0.7
Volts
Volts
Output Winding Diode
Forward Voltage Drop
Bias Winding Diode Forward
Voltage Drop
Ripple to Peak Current Ratio
(0.4 < KRP < 1.0 : 1.0<
KDP<6.0)
VDB
KP
0.70
ENTER TRANSFORMER CORE/CONSTRUCTION VARIABLES
Core Type
Core
EER28
EER28 EER28
P/N:
PC40EER28-Z
Bobbin
AE
EER28_BOBBIN EER28_BOBBIN
0.821
P/N:
0.821 cm^2
BEER-28-1112CPH
Core Effective Cross
Sectional Area
LE
AL
6.4
2870
6.4 cm
2870 nH/T^2
Core Effective Path Length
Ungapped Core Effective
Inductance
BW
M
17.2
3
17.2
17.2 mm
mm
Bobbin Physical Winding
Width
Safety Margin Width (Half
the Primary to Secondary
Creepage Distance)
Number of Primary Layers
L
2
Power Integrations
Tel: +1 408 414 9200 Fax: +1 408 414 9201
www.powerint.com
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