Design Example Report
Title
10 W Power Supply using DPA423P
Specification
Input: 37-57 VDC
Output: 3.3V/2.0A, 5V/200mA, 12V/200mA
Application
VoIP phone
Author
Power Integrations Applications Department
Document
Number
DER-96
Date
September 12, 2005
Revision
1.0
Summary and Features
This document is an engineering prototype report describing a VoIP power supply
utilizing DPA423P.
•
•
•
•
•
•
•
Eliminates LM78xx linear-regulators on 5 V
Low-cost 12 V linear-reg. with short circuit protection provided by main supply
High Efficiency (> 70% at 48 VDC)
Low EMI signature (both radiated and conducted emissions)
Low Parts Count
Built-in input short circuit protection on all outputs
Carefully designed for low EMI
The products and applications illustrated herein (including circuits external to the products and transformer
construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign
patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at
www.powerint.com.
Power Integrations
5245 Hellyer Avenue, San Jose, CA 95138 USA.
Tel: +1 408 414 9200 Fax: +1 408 414 9201
www.powerint.com
DER-96
10 W VoIP
September 12, 2005
Table Of Contents
1
2
3
4
Introduction................................................................................................................. 4
Power Supply Specification ........................................................................................ 5
Schematic................................................................................................................... 6
Circuit Operation ........................................................................................................ 7
4.1
General ............................................................................................................... 7
4.2
Description .......................................................................................................... 7
5 BOM ........................................................................... Error! Bookmark not defined.
6 Layout....................................................................................................................... 11
7 Transformer Design Spreadsheet ............................................................................ 12
8 Transformer Specification......................................................................................... 14
8.1
Transformer Winding......................................................................................... 14
8.2
Electrical Specifications..................................................................................... 14
8.3
Materials............................................................................................................ 14
8.4
Transformer Build Diagram ............................................................................... 15
8.5
Transformer Construction.................................................................................. 15
8.5.1
WD#3 Copper Foil build diagram: .............................................................. 16
9 Inductor Specification ............................................................................................... 17
9.1
Inductor Winding ............................................................................................... 17
9.2
Electrical Specifications..................................................................................... 17
9.3
Materials............................................................................................................ 17
9.4
Inductor Footprint Diagram................................................................................ 18
9.5
Inductor Construction ........................................................................................ 18
10
Performance ......................................................................................................... 19
10.1 Efficiency........................................................................................................... 19
10.2 Regulation vs. Load........................................................................................... 20
10.3 Regulation vs. Load........................................................................................... 21
10.4 Raw Performance Data ..................................................................................... 22
10.5 Thermal Performance........................................................................................ 24
11
Waveforms............................................................................................................ 25
11.1 Drain Current and Voltage................................................................................. 25
11.2 Output Transient Load Response ..................................................................... 26
11.3 Output Ripple Voltage ....................................................................................... 27
11.4 Output Voltage Start-up Profile ......................................................................... 28
12
Conducted EMI ..................................................................................................... 30
12.1 230V High Line EMI .......................................................................................... 30
13
Radiated EMI scans.............................................................................................. 31
14
Revision History.................................................................................................... 32
Page 2 of 33
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DER-96
10 W VoIP
September 12, 2005
Important Notes:
Although this board is designed to satisfy safety isolation requirements, the engineering
prototype has not been agency approved. Therefore, all testing should be performed
using an isolated source to provide power to the prototype board.
Design Reports contain a power supply design specification, schematic, bill of materials,
and transformer documentation. Performance data and typical operation characteristics
are included. Typically only a single prototype has been built.
Page 3 of 33
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DER-96
10 W VoIP
September 12, 2005
1 Introduction
This document is an engineering prototype report describing a VoIP prototype power
supply utilizing DPA423P. The power supply delivers 10 W continuous from an input of
37 to 57 VDC.
The design has been optimized to minimize radiated EMI emissions.
In the EMI section of the report it can be seen that there is a dramatic improvement in
radiated EMI over the existing production DPA423 design.
This document provides complete design information including specification, schematic,
bill of material and transformer design and construction information. The document also
provides performance information.
Page 4 of 33
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10 W VoIP
September 12, 2005
2 Power Supply Specification
Description
Input
Voltage
Under-Voltage
Over-Voltage
Output
Output Voltage 1
Output Ripple Voltage 1
Output Current 1
Output Voltage 2
Output Ripple Voltage 2
Symbol
Min
VIN
VIN_UV
VIN_OV
37
VOUT1
VRIPPLE1
IOUT1
3.135
VOUT2
4.75 5
VRIPPLE2
0
Output Voltage 3
VOUT3
11.4
Total Output Power
Average Output Power
Average Output Power
Average Output Power
Average Output Power
Average Output Power
Full Load Efficiency
3.3
0
IOUT2
Output Current 3
12
VRIPPLE3
IOUT3
Max
Units
57
VDC
VDC
VDC
3.465
100
2
V
mVp-p
A
20 MHz bandwidth
5.25
V
± 5%
100
mVp-p
20 MHz bandwidth
200
mA
12.6
V
± 5%
250
mVp-p
20 MHz bandwidth
200
mA
34
N/A
Output Current 2
Output Ripple Voltage 3
Typ
0
POUT1
POUT2
POUT2
6.6
1
2.4
10
POUT_TOTAL
POUT_FAULT
η
Comment
± 5%
W
W
W
W
W
%
70
Environmental
Conducted EMI
Meets CISPR22B / EN55022B
Designed to meet IEC950, UL1950
Class II
Safety
Ambient Temperature
Page 5 of 33
TAMB
0
CONFIDENTIAL
40
o
C
Forced airflow
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September 12, 2005
Schematic
Figure 1 – Schematic
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10 W VoIP
September 12, 2005
4 Circuit Operation
4.1 General
The power supply uses a DPA423 device (U1), with integrated MOSFET and controller,
in an isolated flyback configuration. The circuit also uses the under-voltage shutdown
feature of the device along with current limit setting to minimize transformer size. The
device operates at a switching frequency of 300 kHz.
4.2 Description
The input fuse F1 protects the supply against catastrophic failure – although the built-in
protection features of the DPA-Switch should render this redundant.
The components C1, C2 and L7 form a pi-filter to limit both conducted and radiated EMI
emissions. These components work to limit EMI emissions in conjunction with y-capacitor
C16 and the shielding in the transformer. Resistor R1 programs the input under voltage
startup threshold (and over voltage shutdown voltage). Diode D1, R7, C4, R2, and R3
implement an RCD clamp circuit to limit the leakage inductance spike on the Drain pin.
Capacitor C3 and resistor R4 implement a snubber to limit high frequency ringing on the
due to drain switching. Diode D2, R5 and C6 implement a bias voltage supply to provide
operating power to the DPA-Switch (U4) with integrated PWM, controller and main
switching MOSFET. Resistor R6 and C5 provide diode snubber for D2. Resistor R20
programs the current limit of the DPA-Switch. Capacitors C7 and C8 provide device
decoupling with C8 also program the startup and auto-restart period of the device.
Resistor R8 provides feedback compensation in conjunction with C8. The inductance of
transformer T1 provides the energy storage and conversion component of the circuit.
The 3.3 V output is rectified and filtered by diode D8 and capacitors C10, C11 with C12
provided output decoupling. The 5 V output is DC-stacked on the regulated DC output of
3.3 V and is rectified and filtered by diode D6 and capacitors C13 with capacitor C18
providing output decoupling. The 12 V output is AC-stacked on the 5 V transformer
winding and is rectified and filtered by diode D7 and capacitor C14 with capacitor C17
providing output decoupling. Transistor Q2 and components R15, R26, R27, R28, C24,
U4 implement a linear regulator to eliminate peak charging voltage from the 12 V output.
Resistor R26, D12, D13 and D14 all form pre-load networks between the outputs to
improve cross-regulation. Components R21, C21, R22, C22, R23 and C23 provide
snubbing on output diodes. Diode pulls down the 5 V output when 12 V output is shorted
thus forcing DPA-switch auto-restart. Using this diode removes the need for short-circuit
protection in the 12 V linear regulator circuit.
Resistors R11 and R10 sense the voltages on 5 V and 3.3 V outputs respectively. In
conjunction with R12 they provide the input signal for the LM431 (U3) reference.
Components R13 and C15 provide compensation for U3, to make sure that it’s frequency
response is limited only to low-frequency signals. Resistor R9 programs the highfrequency gain of the control loop and with opto-diode U2A transmits the feedback signal.
Diode D3 and C9 provide a soft-finish circuit to limit output overshoot at startup. Diode D4
Page 7 of 33
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September 12, 2005
discharges C9 when the output of the power supply drops out of regulation. Optotransistor U2B feeds the control signal back to the DPA-Switch.
Page 8 of 33
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DER-96
10 W VoIP
September 12, 2005
5 Bill Of Materials
Item Qty.
Ref.
Description
Mfg Part Number
Mfg
1
2 C1 C2
39 uF, 63, Electrolytic, Low ESR, 610
mOhm, (6.3 x 15)
LXZ63VB39RM515LL United Chemi-Con
2
1 C3
470 pF, 100 V, Ceramic, X7R
ECU-S2A471KBA
Panasonic
3
1 C4
22 nF, 100 V, Ceramic, X7R
ECU-S2A223KBA
Panasonic
4
1 C5
5
1 C6
470 pF 50 V, Ceramic, X7R, 0603
ECJ-1VC1H471J
Panasonic
10 uF, 16 V, Electrolytic, Gen. Purpose, (5 x KME16VB10RM5X11
11)
LL
United Chemi-Con
6
1 C7
7
1 C8
8
1 C9
C10 C11
4 C12 C18
10
1 C13
11
1 C14
220 nF, 25 V, Ceramic, X7R, 0805
ECJ-2YB1E224K
47 uF, 10 V, Electrolytic, Gen. Purpose, (5 x KME10VB22RM5X11
11)
LL
33 uF, 10 V, Electrolytic, Gen. Purpose, (5 x KME10VB33RM5X11
11)
LL
680 uF, 10 V, Electrolytic, Very Low ESR,
56 mOhm, (8 x 15)
KZE10VB681MH15LL
220 uF, 10 V, Electrolytic, Very Low ESR,
130 mOhm, (6.3 x 11)
KZE10VB221MF11LL
100 uF, 10 V, Electrolytic, Very Low ESR,
300 mOhm, (5 x 11)
KZE10VB101ME11LL
12
1 C15
100 nF, 50 V, Ceramic, X7R, 0805
ECU-V1H221KBN
Panasonic
13
1 C16
330 pF, Ceramic Y1
440LT33
Vishay
14
1 uF, 25 V, Ceramic, X7R, 1206
ECJ-3YB1E105K
Panasonic
15
1 C17
C21 C22
3 C23
100 pF 50 V, Ceramic, X7R, 0603
ECJ-1VC1H101J
Panasonic
16
1 C24
ECU-S1H104KBB
Panasonic
17
1 D1
100 nF, 50 V, Ceramic, X7R
600 V, 1 A, Rectifier, Glass Passivated, 2
us, DO-41
1N4005GP
Vishay
18
3 D2 D3 D4 75 V, 0.15 A, Fast Switching, 4 ns, MELF
LL4148
Diode Inc.
19
1 D6
100 V, 1 A, Schottky, DO-41
SB1100
20
1 D7
60 V, 1.1 A, Schottky, DO-41
11DQ06
Fairchild
International
Rectifier
21
1 D8
40 V, 5 A, Schottky, DO-201AD
SB540
Vishay
22
100 V, 1 A, Rectifier, DO-41
1N4002
50 V, 1 A, Rectifier, Glass Passivated, DO213AA (MELF)
DL4001
Vishay
23
1 D11
D12 D13
3 D15
24
1 D14
20 V, 1 A, Schottky, DO-41
Vishay
25
27
1 F1
1 A, 250V, Slow, TR5
3,721,100,041
J3 J4
2 (FL1, FL2) PCB Terminal Hole, 18 AWG
N/A
10 Position, Fem/Male (5 x 2 header, Top &
1 J6
Bot Entry, 0.1 pitch, Vertical
22-28-4100
28
1 J7
9
26
Page 9 of 33
1N5817
Panasonic
United Chemi-Con
United Chemi-Con
United Chemi-Con
United Chemi-Con
United Chemi-Con
Diodes Inc
Wickman
N/A
Molex
8 Position, Fem/Male (4 x 2) header, Top &
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DER-96
10 W VoIP
September 12, 2005
Bot Entry, 0.1 pitch, Vertical
29
1 L7
520 uH,xA, Powdered Iron Core, Toroidal, 4
Pin
Custom
Custom
30
1 Q2
NPN, Small Signal BJT, 80 V, 0.5 A, TO-92 MPSA06
Fairchild
31
1 R1
619 k, 1%, 1/8 W, Metal Film, 0805
ERJ-6ENF6193V
Panasonic
32
2 R2 R3
100 k, 5%, 1/4 W, Metal Film, 1206
ERJ-8GEYJ104V
Panasonic
33
1 R4
100 R, 5%, 1/8 W, Metal Film, 0805
ERJ-6GEYJ101V
Panasonic
34
1 R5
10 R, 5%, 1/10 W, Metal Film, 0603
ERJ-3GEYJ106V
Panasonic
35
2 R6 R7
100 R, 5%, 1/10 W, Metal Film, 0603
ERJ-3GEYJ101V
Panasonic
36
1 R8
1 R, 1%, 1/16 W, Metal Film, 0603
ERJ-3EKF1004V
Panasonic
37
2 R9 R15
150 R, 5%, 1/10 W, Metal Film, 0603
ERJ-3GEYJ151V
Panasonic
38
1 R10
8.66 k, 1%, 1/16 W, Metal Film, 0603
ERJ-3EKF8661V
Panasonic
39
1 R11
15.8 k, 1%, 1/4 W, Metal Film, 1206
ERJ-8ENF1582V
Panasonic
40
1 R12
10 k, 1%, 1/8 W, Metal Film, 0805
ERJ-6ENF1002V
Panasonic
41
1 R13
1 k, 5%, 1/10 W, Metal Film, 0603
ERJ-3GEYJ102V
Panasonic
42
9.53 k, 1%, 1/4 W, Metal Film, 1206
ERJ-8ENF9531V
Panasonic
43
1 R20
R21 R22
3 R23
10 R, 5%, 1/10 W, Metal Film, 0603
ERJ-3GEYJ100V
Panasonic
44
0 R24 *NP
1.5 k, 5%, 1/8 W, Metal Film, 0805
ERJ-6GEYJ152V
Panasonic
45
0 R25 *NP
150 k, 1%, 1/16 W, Metal Film, 0603
ERJ-3EKF1503V
Panasonic
46
1 R26
1 R, 5%, 1/8 W, Metal Film, 0805
ERJ-6GEYJ1R0V
Panasonic
47
1 R27
26.1 k, 1%, 1/4 W, Metal Film
MFR-25FBF-26K1
Yageo
48
1 R28
10 k, 1%, 1/4 W, Metal Film
MFR-25FBF-10K0
Yageo
49
1 R29
3.3 k, 5%, 1/8 W, Carbon Film
CFR-12JB-3K3
50
1 T1
Bobbin, EFD20, Horizontal, 8 pins
YW-272-03B
Yageo
Yih-Hwa
Enterprises
51
1 U1
DPA-Switch, DPA423P, DIP-8
DPA423P
Power Integrations
52
1 U2
53
1 U3
54
1 U4
Opto coupler, 35 V, CTR 80-160%, 4-DIP ISP817A, PC817X1
2.495 V Shunt Regulator IC, 2%, -40 to
85C, SOT23
LM431AIM
2.495 V Shunt Regulator IC, 2%, 0 to 70C,
TO-92
TL431CLP
Isocom, Sharp
National
Semiconductor
Texas Instruments
68 Total
Page 10 of 33
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DER-96
6
10 W VoIP
September 12, 2005
Layout
Figure 2 – PC-Board Layout (see schematic for *MP and *NP parts)
Page 11 of 33
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10 W VoIP
September 12, 2005
7 Transformer Design Spreadsheet
DCDC_DPASwitch_
061704; Rev.1.11;
Copyright Power
Integrations Inc.
2004
INPUT
INFO
OUTPUT UNITS
DPASwitch_Flyback_061704 - Continuous/Discontinuous mode Spreadsheet.
Copyright 2004 Power Integrations
App140569 - EFD20 - 010605a
ENTER APPLICATION VARIABLES
VDCMIN
VDCMAX
VO
37
57
3.3
Volts
Volts
Volts
PO
n
Z
VB
10 Comment
0.8
Watts
0.7
14
Volts
Minimum DC Input Voltage
Maximum DC Input Voltage
Output Voltage
Verify temperature rise for continuous power. P and G packages may be thermally
limited
Efficiency Estimate
Loss Allocation Factor, (0.7 Recommended)
Bias Voltage (Recommended between 12V and 18V)
UV AND OV PARAMETERS
min
30.8802
33.11235
77.1176
VUVOFF
VUVON
VOVON
VOVOFF
RL
max
34.06899
35.66338
97.52584
637.7573
Volts
Volts
Volts
Volts
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
DPA423P
#N/A
#N/A
F
#N/A
38
0.80
16VDC
Power Out 6W
1.34
Amps
Hertz
38 Volts
0.8
0.928 Amps
9.501216 k-Ohms
Volts
Volts
Volts
1
0.45
0.7
0.40
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
Core Manuf
Bobbin Manuf
Core
Bobbin
AE
LE
AL
BW
M
L
NS
Page 12 of 33
Selected Transformer Core
efd20
EFD20
EFD20_Bob
0.31
4.7
1200
13.5
0
2
3
P/N:
P/N:
cm^2
cm
nH/T^2
mm
mm
CONFIDENTIAL
EFD20-3F3-Exxx-xx
CPHS-EFD20-1S-10P-T
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
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10 W VoIP
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CURRENT WAVEFORM SHAPE PARAMETERS
DMAX
IAVG
IP
IR
IRMS
0.513514
0.337838
0.822368
0.328947
0.476332
Maximum Duty Cycle
Amps
Amps
Amps
Amps
Average Primary Current
Peak Primary Current
Primary Ripple Current
Primary RMS Current
TRANSFORMER PRIMARY DESIGN PARAMETERS
LP
NP
NB
ALG
BP
BM
BAC
ur
LG
BWE
144.7851
30.4
11.76
156.6667
1425.727
1263.441
252.6882
1447.793
0.216191
27
uHenries
nH/T^2
Gauss
Gauss
Gauss
mm
mm
Primary Inductance
Primary Winding Number of Turns
Bias Winding Number of Turns
Gapped Core Effective Inductance
Peak Flux density during transients (Limit to 3000 Gauss)
Maximum Flux Density
AC Flux Density for Core Loss Curves (0.5 X Peak to Peak)
Relative Permeability of Ungapped Core
Gap Length (Lg >> 0.051 mm)
Effective Bobbin Width
TRANSFORMER SECONDARY DESIGN PARAMETERS
ISP
ISRMS
IO
IRIPPLE
8.333333
4.698092
3.030303
3.590172
Amps
Amps
Amps
Amps
Peak Secondary Current
Secondary RMS Current
Power Supply Output Current
Output Capacitor RMS Ripple Current
VOLTAGE STRESS PARAMETERS
VDRAIN
PIVS
PIVB
156.8 Volts
8.925 Volts
36.05 Volts
Maximum Drain Voltage (Includes Effect of Leakage Inductance)
Output Rectifier Maximum Peak Inverse Voltage
Bias Rectifier Maximum Peak Inverse Voltage
ADDITIONAL OUTPUTS
V_OUT2
VD_OUT2
N_OUT2
PIV_OUT2
V_OUT3
VD_OUT3
N_OUT3
PIV_OUT3
1.7330
0.8000
Volts
Volts
6.9
0.7
2.0264
5.5325 Volts
Volts
Volts
6.08
18.3 Volts
Auxiliary Output Voltage
Auxiliary Diode Forward Voltage Drop
Auxiliary Number of Turns
Auxiliary Rectifier Maximum Peak Inverse Voltage
Auxiliary Output Voltage
Auxiliary Diode Forward Voltage Drop
Auxiliary Number of Turns
Auxiliary Rectifier Maximum Peak Inverse Voltage
Note1: the output Vout2 is DC-stacked on top of Vout1 (after the Vout1 rectifier diode),
the output Vout3 is AC-stacked on top of the Vout2 winding (before Vout2 rectifier diode).
Page 13 of 33
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DER-96
10 W VoIP
September 12, 2005
8 Transformer Specification
8.1
Transformer Winding
FL2 (J4)
3
W1: 30T
1 x 27 AWG
W6: 6T
1 x 27 AWG
FL1 (J3)
4
8
FLOAT
W3: 1.5T
FOIL ** .
W5: 2T
3 x 27 AWG
2
6
7
1
W2: 12T
1 x 36 AWG
W4: 3T
4 x 27 AWG
5
2
Figure 3 – Transformer Electrical Diagram (** denotes reverse wound)
8.2
Electrical Specifications
Electrical Strength
Primary Inductance
Resonant Frequency
Primary Leakage Inductance
8.3
Non-isolated
Pins 3-4, all other windings open, measured at
300 kHz, 0.4 VRMS
Pins 3-4, all other windings open
Pins 3-4, with Pins 5,6,7,8 shorted, measured at
300 kHz, 0.4 VRMS
N/A
145 µH, 0/+20%
5 MHz (Min.)
5 uH (Max.)
Materials
Item
[1]
[2]
[3a]
[3b]
[3c]
[4]
[6]
[8]
Description
Core: EFD20 ALG=157 nH/t^2 (core 3F3 material)
Bobbin: EFD20 8-pin horizontal
27AWG Doubled insulated
36 AWG Doubled insulated
1 mil foil
Prepared foil – see assembly diagram.
Tape:
Varnish
Page 14 of 33
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DER-96
8.4
10 W VoIP
September 12, 2005
Transformer Build Diagram
Tape
Tape
FL1
W6
FL2
Tape
6
8
W5
5
7
W4
Tape
2
W3
2
1
W2
3
4
W1
Tape
Figure 4 – Transformer Build Diagram
8.5
Transformer Construction
W1
Tape
W2
Tape
W3
Tape
W4
W5
Tape
W6
Outer Wrap
Core Ground
Final Assembly
Page 15 of 33
Start at Pin 4. Wind 30 turns item [3a]. Finish on pin 3
Use layer of item [6].
Start at Pin 1. Wind 12 turns item [3b]. Spread evenly across bobbin.
Finish on pin 2
Use layer of item [6].
Start at Pin 2. Wind reverse direction 1.5 turns of item [4]. Finish winding
and leave floating in stack.
Use layer of item [6].
Start at Pins 7. Wind 3 turns quad-filar item [3a]. Spread evenly across
bobbin. Finish temporarily on pin 1.
Start at Pin 8. Wind 2 turns tri-filar item [3a]. Spread evenly across
bobbin, filling in the gaps in the previous W3. Finish on pin 6.
Move temporary connection from Pin 1 to Pin 5.
Use layer of item [6].
Start at FL2. Wind 6 turns item [3a]. Spread evenly across bobbin. Finish
on FL1.
Wrap windings with 3 layers of tape [item [7].
Use copper self-adhesive tape touching core on all four sides. Make
connection from this tape to pin 2 of bobbin. Note: this is not a “bellyband”, this is instead purely to electrically ground the core
Assemble and secure core halves. Varnish impregnate (item [8]).
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DER-96
10 W VoIP
September 12, 2005
8.5.1 WD#3 Copper Foil build diagram:
Cu Foil 1mil; 13 mm W x 46mm L
1-layer tape folded
44mm
30 AWG
Page 16 of 33
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DER-96
10 W VoIP
September 12, 2005
9 Inductor Specification
9.1
Inductor Winding
4
W1: 15T
1 x 27 AWG
2
3
W2: 15T
1 x 27 AWG
1
Figure 5 – Inductor Electrical Diagram
9.2
Electrical Specifications
Electrical Strength
Primary Inductance
Resonant Frequency
Primary Leakage Inductance
9.3
Non-isolated
Pins 4-2, all other windings open, measured at
300 kHz, 0.4 VRMS
Pins 4-2, all other windings open
Pins 4-2, with Pins 1,2,3,5,6,8 shorted, measured
at 300 kHz, 0.4 VRMS
N/A
520 µH, -0/+20%
3.9 MHz (Min.)
3.5 uH (Max.)
Materials
Item
[1]
[2]
[3a]
[8]
Description
Core: Fair-rite - 5975000201 (diameter 9.5mm, Al=4400)
Bobbin – 8 pin former
27AWG Doubled insulated
Hot-set glue
Page 17 of 33
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DER-96
9.4
10 W VoIP
September 12, 2005
Inductor Footprint Diagram
Figure 6 – Transformer Footprint – Top Side View Diagram
9.5
Inductor Construction
W1
W2
Outer Wrap
Final Assembly
Page 18 of 33
Start at Pin 2. Wind 15 turns item [3a]. Finish on pin 4
Start at Pin 1. Wind 15 turns item [3a]. Finish on pin 3
Wrap windings with 3 layers of tape [item [7].
Assemble and secure core halves. Impregnate (item [8]).
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DER-96
10 W VoIP
September 12, 2005
10 Performance
10.1 Efficiency
Efficiency vs Line/Load
80%
Efficiency (%)
70%
37 VDC
60%
48 VDC
57 VDC
50%
40%
0
2
4
6
8
10
Pout (W)
12
14
16
Figure 7 – Efficiency vs. Input Voltage and Output Load, Room Temperature
Page 19 of 33
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DER-96
10 W VoIP
September 12, 2005
10.2 Regulation vs. Load
Regulation vs Load
107.0%
104.5%
Re
gu 102.0%
lat
io 99.5%
n
(% 97.0%
)
3.3 V 37
VDC
3.3 V 57
VAC
5 V 37
VDC
5 V 57
VDC
94.5%
92.0%
0
2
4
6
8
10
12
14
16
Pout (W)
Figure 8 – Output Regulation vs. Output Load for 3.3 V and 5 V Outputs, Room Temperature
Page 20 of 33
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DER-96
10 W VoIP
September 12, 2005
10.3 Regulation vs. Load
Regulation vs Load
Regulation (%)
105.0%
102.5%
12V 37 VDC
12V 57 VDC
100.0%
97.5%
95.0%
0
2
4
6
8
10
12
14
16
Pout (W)
Figure 9 – Output Regulation vs. Output Load for 12 V Output, Room Temperature
Page 21 of 33
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DER-96
10 W VoIP
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10.4 Raw Performance Data
It can be seen from the data below, that the power supply meets the regulation
requirements even without need for a linear-regulator on the 5 V output. Also the
efficiency of 70.5% at 48 VDC very high compared to alternate solutions.
Vin
(DC)
Iin
(A)
Vout1
(V)
Iout1
(A)
Vout2
(V)
Iout2
(A)
Vout3
(V)
Iout3
(A)
37.6
37.6
37.6
37.6
37.6
37.6
37.6
37.6
37.5
37.5
37.5
37.5
0.021
0.103
0.05
0.139
0.08
0.16
0.12
0.196
0.277
0.335
0.325
0.377
3.3
3.25
3.31
3.29
3.24
3.23
3.28
3.27
3.2
3.2
3.23
3.22
0
0
0
0
0.5
0.5
0.5
0.5
2
2
2
2
5.02
5.11
5.02
5.05
5.14
5.14
5.07
5.06
5.19
5.18
5.13
5.12
0
0
0.2
0.2
0
0
0.2
0.2
0
0
0.2
0.2
11.84
11.21
12.54
11.48
12.48
11.46
12.52
11.66
12.48
12.06
12.52
12.25
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
48.2
48.2
48.2
48.1
48.1
48.1
48.1
48.1
48.1
48.1
48.1
48.1
0.019
0.083
0.042
0.113
0.061
0.128
0.097
0.156
0.214
0.261
0.249
0.292
3.3
3.25
3.31
3.28
3.24
3.23
3.28
3.27
3.2
3.2
3.23
3.23
0
0
0
0
0.5
0.5
0.5
0.5
2
2
2
2
5.04
5.11
5.01
5.05
5.14
5.14
5.07
5.08
5.18
5.18
5.11
5.12
0
0
0.2
0.2
0
0
0.2
0.2
0
0
0.2
0.2
11.87
11.23
12.55
11.48
12.48
11.44
12.52
11.64
12.47
11.94
12.51
12.12
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
57.6
57.6
57.6
57.6
57.6
57.6
57.6
57.6
57.5
57.5
57.5
57.5
0.017
0.069
0.038
0.097
0.051
0.11
0.083
0.134
0.181
0.219
0.207
0.245
3.3
3.25
3.31
3.28
3.24
3.23
3.28
3.27
3.2
3.2
3.23
3.23
0
0
0
0
0.5
0.5
0.5
0.5
2
2
2
2
5.04
5.12
5.01
5.05
5.14
5.14
5.07
5.07
5.18
5.18
5.12
5.12
0
0
0.2
0.2
0
0
0.2
0.2
0
0
0.2
0.2
11.86
11.23
12.55
11.47
12.48
11.44
12.52
11.62
12.48
11.88
12.51
12.05
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
0
0.2
3.31
3.2
0.11
0.3%
-3.0%
3.3%
5.19
5.02
0.17
3.8%
0.4%
3.4%
12.54
11.21
1.33
4.5%
-6.6%
11.1%
Max
Min
Delta
Page 22 of 33
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DER-96
Vnom1=
Vnom2=
%Vout1
(%)
10 W VoIP
3.3 Vnom3=
5
%Vout2
%Vout3
(%)
(%)
September 12, 2005
12
Pin
(W)
Eff
(%)
Pout1
(W)
Pout2
(W)
Pout3
(W)
Pout6
(W)
100.0%
98.5%
100.3%
99.7%
98.2%
97.9%
99.4%
99.1%
97.0%
97.0%
97.9%
97.6%
100.4%
102.2%
100.4%
101.0%
102.8%
102.8%
101.4%
101.2%
103.8%
103.6%
102.6%
102.4%
98.7%
93.4%
104.5%
95.7%
104.0%
95.5%
104.3%
97.2%
104.0%
100.5%
104.3%
102.1%
0.7896
3.8728
1.88
5.2264
3.008
6.016
4.512
7.3696
10.3875
12.5625
12.1875
14.1375
0.0%
57.9%
53.4%
63.3%
53.9%
64.9%
58.8%
67.6%
61.6%
70.1%
61.4%
70.1%
0.0
0.0
0.0
0.0
1.6
1.6
1.6
1.6
6.4
6.4
6.5
6.4
0.0
0.0
1.0
1.0
0.0
0.0
1.0
1.0
0.0
0.0
1.0
1.0
100.0%
98.5%
100.3%
99.4%
98.2%
97.9%
99.4%
99.1%
97.0%
97.0%
97.9%
97.9%
100.8%
102.2%
100.2%
101.0%
102.8%
102.8%
101.4%
101.6%
103.6%
103.6%
102.2%
102.4%
98.9%
93.6%
104.6%
95.7%
104.0%
95.3%
104.3%
97.0%
103.9%
99.5%
104.3%
101.0%
0.9158
4.0006
2.0244
5.4353
2.9341
6.1568
4.6657
7.5036
10.2934
12.5541
11.9769
14.0452
0.0%
56.1%
49.5%
60.8%
55.2%
63.4%
56.9%
66.4%
62.2%
70.0%
62.5%
70.5%
0.0
0.0
0.0
0.0
1.6
1.6
1.6
1.6
6.4
6.4
6.5
6.5
0.0
0.0
0.0
0.0
2.2
0.0
1.0
0.0
0.0
1.0
2.3
0.0
High efficiency
at
0.0
0.0
0.0
0.0
VDC full2.3load 0.0
1.0
0.0
0.0
1.0
2.3
0.0
0.0
0.0
0.0
0.0
2.4
0.0
1.0
0.0
0.0
1.0
2.4
0.0
100.0%
98.5%
100.3%
99.4%
98.2%
97.9%
99.4%
99.1%
97.0%
97.0%
97.9%
97.9%
100.8%
102.4%
100.2%
101.0%
102.8%
102.8%
101.4%
101.4%
103.6%
103.6%
102.4%
102.4%
98.8%
93.6%
104.6%
95.6%
104.0%
95.3%
104.3%
96.8%
104.0%
99.0%
104.3%
100.4%
0.9792
3.9744
2.1888
5.5872
2.9376
6.336
4.7808
7.7184
10.4075
12.5925
11.9025
14.0875
0.0%
56.5%
45.8%
59.1%
55.1%
61.6%
55.5%
64.4%
61.5%
69.7%
62.9%
70.2%
0.0
0.0
0.0
0.0
1.6
1.6
1.6
1.6
6.4
6.4
6.5
6.5
0.0
0.0
1.0
1.0
0.0
0.0
1.0
1.0
0.0
0.0
1.0
1.0
100.3%
97.0%
3.3%
103.8%
100.4%
3.4%
104.5%
93.4%
11.1%
Page 23 of 33
14.1
1.9
12.3
0.0
2.2
0.0
2.3
0.0
2.3
0.0
2.3
0.0
2.4
0.0
2.5
Pout
(W)
0.0
2.2
0.0
2.3
0.0
2.3
0.0
2.3
0.0
2.4
0.0
2.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
2.2
1.0
3.3
1.6
3.9
2.7
5.0
6.4
8.8
7.5
9.9
0.0
2.2
1.0
3.3
48 1.6
3.9
2.7
5.0
6.4
8.8
7.5
9.9
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
70.1%
53.4%
16.7%
CONFIDENTIAL
0.0
2.2
1.0
3.3
1.6
3.9
2.7
5.0
6.4
8.8
7.5
9.9
9.9
1.0
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DER-96
10 W VoIP
September 12, 2005
10.5 Thermal Performance
Temperature Vs Time
Temperature ('C)
100
Ch1 - U1
Ch2 - Amb
80
Ch3 - C11
60
Ch4 - D8
Ch5 - T1
40
20
0
1
10
100
Time (min)
Figure 10 – Thermal Performance of Key Power Supply Components
Time
(Mins.)
0
1
2
4
8
16
37
66
132
U1 (Drain)
('C)
24
44
47
60
63
73
66
73
66
Amb
('C)
24
24
24
24
24
25
26
26
26
Temperature
C11
('C)
25
27
31
36
44
49
51
50
49
D8
('C)
25
43
49
52
63
64
70
65
71
T1
('C)
25
30
35
41
52
58
61
61
62
Figure 11 – Raw Test Data
Page 24 of 33
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DER-96
10 W VoIP
September 12, 2005
11 Waveforms
11.1 Drain Current and Voltage
Figure 12 – 37 VDC, full load
Upper Ch3: Drain Voltage 50 V,
Lowr Ch4: Drain Current 0.5 A / Div,
1 µs / div
Figure 13 – 48 VDC, full load
Upper Ch3: Drain Voltage 50 V,
Lowr Ch4: Drain Current 0.5 A / Div,
1 µs / div
Figure 14 – 57 VDC, full load
Upper Ch3: Drain Voltage 50 V,
Lowr Ch4: Drain Current 0.5 A / Div,
1 µs / div
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DER-96
10 W VoIP
September 12, 2005
11.2 Output Transient Load Response
Figure 15 – 48 VDC, full load (3.3 V 1.6 A to 2.0 A step)
3.3 V Output Voltage
50 mV / Div, 10 ms / div
Figure 16 – 48 VDC, full load (5 V 0.16 A to 0.2 A step)
5 V Output Voltage
20 mV / Div, 10 ms / div
Figure 17 – 48 VDC, full load (12 V 0.16 A to 0.2 A
step)
12 V Output Voltage
50 mV / Div, 10 ms / div
Page 26 of 33
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DER-96
10 W VoIP
September 12, 2005
11.3 Output Ripple Voltage
It can be seen from the waveforms below that the power supply comfortably meets the
output ripple specifications. This is possible even without the need for an output inductor.
Measurements made with 0.1 uF ceramic capacitor in parallel with a 1 uF / 50 V
electrolytic capacitor, and also made using very short lead length connections to the
output pins of the power supply.
Figure 18 – 48 VDC, Full Load
3.3 V Output Ripple, 50 mV,
2 µs / div
Figure 19 – 48 VDC, Full Load
5V Output Ripple, 50 mV,
2 µs / div
Figure 20 – 48 VDC, Full Load
12 V Output Ripple, 50 mV,
2 µs / div
Page 27 of 33
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DER-96
10 W VoIP
September 12, 2005
11.4 Output Voltage Start-up Profile
Figure 21 – 3.3 V Start-up at No Load, 48 VDC
Upper Ch1: 3.3 V output, 1 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
Figure 22 – 3.3 V Start-up at Full Load, 48 VDC
Upper Ch1: 3.3 V output, 1 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
Figure 23 – 5 V Start-up at No Load, 48 VDC
Upper Ch1: 5 V output, 2 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
Figure 24 – 5 V Start-up at Full Load, 48 VDC
Upper Ch1: 5 V output, 2 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
Page 28 of 33
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DER-96
10 W VoIP
Figure 25 – Start-up Profile at No Load, 48 VDC
Upper Ch1: 12 V output, 2 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
Page 29 of 33
CONFIDENTIAL
September 12, 2005
Figure 26 – Start-up Profile at Full Load, 48 VDC
Upper Ch1: 12 V output, 2 V / div,
Lower Ch3: Drain Voltage 50 V / div,
20 ms / div.
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DER-96
10 W VoIP
September 12, 2005
12 Conducted EMI
EMI was tested at room temperature and at 230 VAC input. An AC-DC (48 V output)
adapter was plugged into the LISN (AC-output). The DC-DC converter (using DPA423
was plugged into the 48 VDC output from the AC-DC adapter.
In some tests the output of the DC-DC converter was left floating and in other cases the
output (0 VDC) was connected to Earth ground.
12.1 230V High Line EMI
Figure 27 – 230 VAC - N1 - full system grounded
output - full-load
Figure 28 – 230 VAC - L1 - full system grounded
output - full-load
Figure 29 – 230 VAC - N1 - full system floating
output - full-load
Figure 30 – 230 VAC - L1 - full system floating
output - full-load
Page 30 of 33
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DER-96
10 W VoIP
September 12, 2005
13 Radiated EMI scans
As can be seen from the radiated EMI scans below, the new board performs extremely
well compared to the original DPA423 power supply. This is because of optimal layout
and power supply filtering (including transformer shielding design).
The measurements were made in an open-field test site, with the AC-adapter (which
outputs 48 VDC). This AC-adapter was connected to 115 VAC via a LISN and the output
48 VDC was input to the DPA423 DC-DC converter.
Local baseline
radio interferance
Figure 31 – Radiated no-power Baseline
Figure 32 – Original board with DPA423 and ACadapter (230 VAC) – Output Floating
Figure 33 – New prototype board using DPA423 and
AC-adapter (230 VAC) – Output Floating
Figure 34 – New prototype board using DPA423 and
AC-adapter (230 VAC) – Output Hard Grounded
Page 31 of 33
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DER-96
10 W VoIP
September 12, 2005
14 Revision History
Date
September 12, 2005
Page 32 of 33
Author
RM
Revision
1.0
CONFIDENTIAL
Description & changes
Initial release
Reviewed
VC / AM
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DER-96
10 W VoIP
September 12, 2005
For the latest updates, visit our Web site: www.powerint.com
Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your
use of any information, device or circuit described herein nor does it convey any license under its patent rights or the
rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES HEREIN AND SPECIFICALLY DISCLAIMS
ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS.
PATENT INFORMATION
The products and applications illustrated herein (including circuits external to the products and transformer
construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign
patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at
www.powerint.com.
The PI Logo, TOPSwitch, TinySwitch, LinkSwitch, and EcoSmart are registered trademarks of Power
Integrations. PI Expert and DPA-Switch are trademarks of Power Integrations.
© Copyright 2004, Power Integrations.
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[email protected]
TAIWAN
17F-3, No. 510,
Chung Hsiao E. Rd., Sec. 5,
Taipei, Taiwan 110, R.O.C.
Phone: +886-2-2727-1221
Fax:
+886-2-2727-1223
e-mail:
[email protected]
CHINA (SHANGHAI)
Rm 807, Pacheer,
Commercial Centre,
555 Nanjing West Road,
Shanghai, 200041, China
Phone: +86-21-6215-5548
Fax:
+86-21-6215-2468
e-mail:
[email protected]
INDIA (TECHNICAL SUPPORT)
Innovatech
261/A, Ground Floor
7th Main, 17th Cross,
Sadashivanagar
Bangalore, India, 560080
Phone: +91-80-5113-8020
Fax:
+91-80-5113-8023
e-mail: [email protected]
KOREA
8th Floor, DongSung Bldg.
17-8 Yoido-dong,
Youngdeungpo-gu,
Seoul, 150-874, Korea
Phone: +82-2-782-2840
Fax:
+82-2-782-4427
e-mail:
[email protected]
UK (EUROPE & AFRICA
HEADQUARTERS)
1st Floor, St. James’s House
East Street
Farnham, Surrey GU9 7TJ
United Kingdom
Phone: +44-1252-730-140
Fax:
+44-1252-727-689
e-mail: [email protected]
CHINA (SHENZHEN)
Rm# 1705, Bao Hua Bldg.
1016 Hua Qiang Bei Lu,
Shenzhen, Guangdong,
518031, China
Phone: +86-755-8367-5143
Fax:
+86-755-8377-9610
e-mail:
[email protected]
ITALY
Via Vittorio Veneto 12, Bresso,
Milano,
20091, Italy
Phone: +39-028-928-6001
Fax: +39-028-928-6009
e-mail: [email protected]
SINGAPORE
51 Newton Road,
#15-08/10 Goldhill Plaza,
Singapore, 308900
Phone: +65-6358-2160
Fax:
+65-6358-2015
e-mail:
[email protected]
m
APPLICATIONS HOTLINE
World Wide +1-408-414-9660
APPLICATIONS FAX
World Wide +1-408-414-9760
ER or EPR template – Rev 3.6 – Single sided
Page 33 of 33
CONFIDENTIAL
Power Integrations
Tel: +1 408 414 9200 Fax: +1 408 414 9201
www.powerint.com