EPR-86 Datasheet, PDF (13/28 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP 86 - 6.6 W Multi-Class Powered Device (PD) for Power over Ethernet (PoE) Using DPA-Switch-(DPA423G)

13-Apr-2006
EP-86 – 6.6 W, 3.3 V, 2 A PoE Powered Device
7 Transformer Design Spreadsheet
DCDC_DPASwitch_Flyback_071405; Rev.2.7;
Copyright Power Integrations 2005
ENTER APPLICATION VARIABLES
VDCMIN
VDCMAX
VO
PO
n
Z
INPUT
INFO OUTPUT UNITS
36
Volts
57
Volts
3.3
Volts
6.6 Comment
0.8
Watts
0.7
DPASwitch_Flyback_071405 - Continuous/Discontinuous
mode Spreadsheet. Copyright 2005 Power Integrations
DC-DC Converter
Minimum DC Input Voltage
Maximum DC Input Voltage
Output Voltage (main)
Verify temperature rise for continuous power. P and G
packages may be thermally limited
Efficiency Estimate
Loss Allocation Factor, (0.7 Recommended)
VB
14
Volts Bias Voltage (Recommended between 12V and 18V)
UV AND OV PARAMETERS
VUVOFF
VUVON
VOVON
VOVOFF
RL
min
30.0
32.2
74.9
max
33.1 Volts
34.7 Volts
- Volts
94.7 Volts
619.0 k-Ohms
Minimum undervoltage On-Off threshold
Maximum undervoltage Off-On threshold (turn-on)
Minimum overvoltage Off-On threshold
Maximum overvoltage On-Off threshold (turn-off)
ENTER DPASWITCH VARIABLES
DPASWITCH
Chosen Device
ILIMITMAX
Frequency
fS
VOR
KI
ILIMITEXT
RX
VDS
VD
VDB
KRP/KDP
DPA423G
DPA423G
1.16
F
375000
38
0.7
1
0.5
0.7
0.62
16VDC
Power Ou 6W
1.34
Amps
Hertz
38 Volts
0.7
0.812 Amps
11.0 k-Ohms
Volts
Volts
Volts
36 VDC
13W
From DPASWITCH Data Sheet
Enter 'F' for fS = 400KHz and 'L' for fS = 300KHz
DPASWITCH Switching Frequency
Reflected Output Voltage
Current Limit Reduction Factor
Minimum External Current limit
Resistor from X pin to source to set external current
limit
DPASWITCH on-state Drain to Source Voltage
Output Winding Diode Forward Voltage Drop
Bias Winding Diode Forward Voltage Drop
Ripple to Peak Current Ratio (0.2 < KRP < 1.0 : 1.0<
KDP<6.0)
ENTER TRANSFORMER CORE/CONSTRUCTION VARIABLES
Core Type
ER14.5
Core Manuf
Bobbin Manuf
Core
ER14.5
P/N:
Bobbin
ER14.5_Bobbin
P/N:
AE
0.176 cm^2
LE
1.9 cm
AL
1400 nH/T^2
BW
1.9 mm
M
0
mm
L
2
NS
2
ER14.5-3F3-S
CPVS-ER14.5-1S-10P
Core Effective Cross Sectional Area
Core Effective Path Length
Ungapped Core Effective Inductance
Bobbin Physical Winding Width
Safety Margin Width (Half the Primary to Secondary
Creepage Distance)
Number of Primary Layers
Number of Secondary Turns
Page 13 of 28
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