POWERINT RD5

®
RD5
®
TOPSwitch-II
Reference Design Board
85 to 265 VAC Input, 20W (30W Peak) Output
Product Highlights
Low Cost Production Worthy Reference Design
• Only 22 components!
• Single sided board
• Low cost thru-hole components
• Fully assembled and tested
• Easy to evaluate and modify
• Extensive performance data
• Up to 80% efficiency
• Light weight – no heat sink required for TOPSwitch-II
1.69 in.
(43 mm)
3.57 in. (91 mm)
Fully Protected by TOPSwitch-II
• Primary safety current limit
• Output short circuit protection
• Thermal shutdown protects entire power supply
Designed for World Wide Operation
• Designed for IEC/UL safety requirements
• Meets VDE Class B EMI specifications
Description
The RD5 reference design board is an example of a very low
cost production worthy power supply design using the
TOPSwitch family of Three-terminal Off-line PWM Switchers
from Power Integrations. It is intended to help TOPSwitch
users to develop their products quickly by providing a basic
design that can be easily modified to fit a particular application.
In most cases, a minor change to the transformer for a different
output voltage is all that is needed. Multiple output voltages are
obtained just as easily. A constant current or constant power
output may be implemented with the addition of a few low cost
components.
Typical applications include AC-DC adapters for laptops,
notebooks and PDAs, battery chargers for cellular telephones,
power tools and camcorders, VTR/VCR, video game, appliance
and satellite decoder power supplies.
1.06
in.
(27 mm)
PI-2058-041698
Figure 1. RD5 Board Overall Physical Dimensions.
PARAMETER
Input Voltage Range
Input Frequency Range
LIMITS
85 to 265 VAC
47 to 440 Hz
Temperature Range
Output Voltage (Io = 1.0A)
Output Power (continuous)
0 to 50°C
12 V ± 5%
25˚C
20W
50˚C
15W
Output Power (peak)
30W
Line Regulation (85-265 VAC)
± 1%
Load Regulation (10%-100%)
± 1%
Efficiency
78%
Output Ripple Voltage
Safety
EMI
± 60 mV MAX
IEC 950 / UL1950
VDE B (VFG243 B)
CISPR22
Figure 2. Table of Key Electrical Parameters.
July 1997
RD5
7, 8
+12V
C2
560 µF
35 V
VR1
P6KE200
5, 6
L2
19 mH
BR1
600 V
D3
1N4148
2
C1
47 µF
400 V
J1
D
F1
3.15 A
S
U1
TOP224P
R1
39 Ω
4
C4
0.1 µF
TOPSwitch-II
CONTROL
C3
220 µF
35 V
RTN
D1
UF4005
C6
0.1 µF
250 VAC
L1
3.3 µH
D2
50SQ100
1
T1
R2
150 Ω
3
C
C5
47 µF
R3
6.8 Ω
U2
PC817A
C7
1 nF
250 VAC
Y1
L
VR2
1N5241B
11 V
N
PI-2053-041698
Figure 3. Schematic Diagram of the 12V RD5 Power Supply.
BR1
VR1
C1
D2
T1
F1
RD5
S/N
R2
U1
POWER
INTEGRATIONS
INC.
J1
L1
C2
D1
L2
C6
C4
C7
R1
VR2
Rev. A
R3
C5
J2
+
C3
D3
U2
COMPONENT SIDE SHOWN
PI-2059-062697
Figure 4. Component Legend of the RD5.
General Circuit Description
The RD5 is a low-cost, flyback switching power supply using
the TOP224P integrated circuit. The circuit shown in Figure 3
produces a 12 V, 20 W power supply that operates from 85 to
265 VAC input voltage. The 12 V output is directly sensed by
optocoupler U2 and Zener diode VR2. The output voltage is
determined by the Zener diode (VR2) voltage and the voltage
drops across the optocoupler (U2) LED and resistor R1. Other
output voltages are also possible by adjusting the transformer
34
A
7/97
turns ratios and value of Zener diode VR2.
AC power is rectified and filtered by BR1 and C1 to create the
high voltage DC bus applied to the primary winding of T1. The
other side of the transformer primary is driven by the integrated
high-voltage MOSFET within the TOP224. D1 and VR1
clamp the leading-edge voltage spike caused by transformer
leakage inductance to a safe value and reduce ringing. The
RD5
Component Listing
Reference
Value
Part Number
Manufacturer
BR1
C1
C2
C3
C4
C5
C6
C7*
600 V, 2 A
47 µF, 400 V
560 µF, 35 V
220 µF, 35 V
0.1 µF, 50 V
47 µF, 10 V
0.1 µF, 250 VAC, X
1.0 nF, 400 VAC, Y1*
D1
D2
D3
L1
L2
R1
R2
R3
T1**
U1
U2
VR1
VR2
F1
600 V, 1A, UFR
100 V, 5A, Schottky
75 V, Switching
3.3 µH, 6.5 A
19 mH, 400 mA
39 Ω, 1/4 W
150 Ω, 1/4 W
6.8 Ω, 1/4 W
2KBPC06M
381LX470M400H012
ECA-1VFQ561
ECE-A1VGE221
RPE131R104M50
ECE-A1AG470
F1772-410-2000
DE1110E102M ACT4K-KD
(or WKP102MCPE.OK
(or PME294RB4100M
UF4005
50SQ100
1N4148
622LY-3R3M
ELF15N005A
5043CX39R00J
5043CX150R0J
5043CX6R800J
TRD5
TOP224P
PC817A
P6KE200
1N5241B
19372K, 3.15A
General Instrument
Cornell-Dubilier
Panasonic
Panasonic
Murata
Panasonic
Roederstein
Murata
Roederstein)
Rifa)
General Instrument
International Rectifier
National Semiconductor
Toko
Panasonic
Philips
Philips
Philips
Custom
Power Integrations
Sharp
General Instrument
Motorola
Wickman
200 V Zener TVS
11 V Zener
3.15 A, 250 VAC
Figure 5. Parts List for the RD5 (* Two Series Connected, 2.2 nF, Y2-Capacitors Such as Murata DE7100F222MVA1-KC can replace C7).
** T1 is available from Premier Magnetics (714) 362-4211 as P/N POL-12017, and from Coiltronics (561) 241-7876 as P/N CTX00-13742.
power secondary winding is rectified and filtered by D2, C2,
L1, and C3 to create the 12 V output voltage. R2 and VR2
provide a slight pre-load on the 12 V output to improve load
regulation at light loads. R2 also provides bias current for Zener
VR2 to improve regulation. The bias winding is rectified and
filtered by D3 and C4 to create a bias voltage to the TOP224P.
L2 and Y1-capacitor C7 attenuate common-mode emission
currents caused by high-voltage switching waveforms on the
DRAIN side of the primary winding and the primary to secondary
capacitance. L2 and C6 attenuate differential-mode emission
currents caused by the fundamental and harmonics of the
primary current waveform. C5 filters internal MOSFET gate
drive charge current spikes on the CONTROL pin, determines
the auto-restart frequency, and together with R1 and R3,
compensates the control loop.
10% to 100% of rated load current. The TOPSwitch on–chip
overtemperature protection circuit will safely shut down the
power supply under persisting overload conditions. Below
minimum load, the 12 V output rises slightly due to the
TOPSwitch minimum duty cycle.
Line Regulation (Figure 7) - The amount of change in the DC
output voltage for a given change in the AC input voltage is
called line regulation. The maximum change in output voltage
is within ± 1%.
Efficiency (Line Dependent) – Efficiency is the ratio of the
output power to the input power. The curves in Figures 8 and 9
show how the efficiency changes with input voltage.
The circuit performance data shown in Figures 6-18 were
measured with AC voltage applied to the RD5.
Efficiency (Load Dependent) – The curves in Figures 10 and 11
show how the efficiency changes with output power for 115
VAC and 230 VAC inputs.
Load Regulation (Figure 6) – The amount of change in the DC
output voltage for a given change in output current is referred
to as load regulation. The 12 V output stays within ±1% from
Power Supply Turn On Sequence – The internal switched, highvoltage current source provides the initial bias current for
TOPSwitch when power is first applied. The waveforms shown
A
7/97
35
RD5
General Circuit Description (cont.)
in Figure 12 illustrate the relationship between the high-voltage
DC bus and the 12 V output voltage. Capacitor C1 charges to
the peak of the AC input voltage before TOPSwitch turns on.
The delay of 160 ms (typical) is caused by the time required to
charge the auto-restart capacitor C5 to 5.8 V. At this point the
power supply turns on as shown.
Figure 13 shows the output voltage turn on transient as well as
a family of curves associated with an additional soft-start
capacitor. The soft-start capacitor is placed across VR2 and can
range in value from 4.7 uF to 47 uF as shown.
Line frequency ripple voltage is shown in Figure 14 for 115
VAC input and 20 W output. Switching frequency ripple
voltage is shown in Figure 15 for the same test condition.
The power supply transient response to a step load change from
1.25 to 1.67 A (75% to 100%) is shown in Figure 16. Note that
the response is quick and well damped.
The RD5 is designed to meet worldwide safety and EMI (VDE
B) specifications. Measured conduction emissions are shown
in Figure 17 for 115 VAC and Figure 18 for 230 VAC.
Thermal Considerations
15 W output is outlined on the non-component side of the board,
and is approximately 0.56 in2 (3.6 cm2). The RD5 printed circuit
board utilizes 2 oz. copper cladding. Printed circuit boards with
lighter cladding will require apertures in the solder mask to
build-up effective trace thickness.
Transformer Specification
The electrical specifications and construction details for
transformer TRD5 are shown in Figures 19 and 20. Transformer
TRD5 is supplied with the RD5 reference design board. This
design utilizes an EI25 core and a triple insulated wire secondary
winding. The use of triple insulated wire allows the transformer
to be constructed using a smaller core and bobbin than a
conventional magnet wire design due to the elimination of the
margins required for safety spacing in a conventional design.
If a conventional margin wound transformer is desired, the
design of Figures 21-22 can be used. This design (TRD5-1)
uses a EEL22 core and bobbin to accommodate the 3 mm
margins required to meet international safety standards when
using magnet wire rather than triple insulated wire, and has the
same pinout and printed circuit foot print as TRD5. The
transformer is approximately 50% taller than the triple insulated
wire design due to the inclusion of creepage margins required
to meet international safety standards.
The RD5 utilizes the printed circuit copper for TOPSwitch
heatsinking. For 20 W output, the heatsink area is approximately
1.25 in2 (8 cm2). The copper area required for heatsinking at
100
90
0
0.5
1
1.5
2
Load Current (A)
110
VIN = 230 VAC
100
90
0
0.5
1
1.5
Load Current (A)
Figure 6. Load Regulation
36
A
7/97
2
110
PI-2063-070297
VIN = 115 VAC
Output Voltage (% of Nominal)
PI-2062-070297
Output Voltage (% of Nominal)
110
100
90
IL = 1.67 A
50
100
150
200
250
300
Input Voltage (VAC)
110
100
90
IL = 0.33 A
50
100
150
200
250
Input Voltage (VAC)
Figure 7. Line Regulation
300
RD5
Po = 4 W
60
40
20
80
60
40
20
0
0
100
200
0
300
Figure 8. Efficiency vs. Input Voltage, 20 W Output
100
VIN = 230 VAC
Output Efficiency (%)
80
300
Figure 9. Efficiency vs. Input Voltage, 4 W Output
PI-2066-070297
VIN = 115 VAC
200
Input Voltage (VAC)
Input Voltage (VAC)
100
100
PI-2067-070297
0
60
40
20
80
60
40
20
0
0
0
5
10
15
0
20
PI-2068-070297
50
0
OUTPUT
VOLTAGE
0 µF
10
Output Voltage (V)
100
15
15
20
Figure 11. Efficiency vs. Output Power, 230 VAC Input
Figure 10. Efficiency vs. Output Power, 115 VAC Input
150
10
Output Power (W)
Output Power (W)
DC BUS VOLTAGE
5
PI-2069-070297
Output Efficiency (%)
PI-2065-070297
80
Output Efficiency (%)
Po = 20 W
Output Efficiency (%)
100
PI-2064-070297
100
4.7 µF
10 µF 22 µF
47 µF
8
6
4
2
0
10
5
0
0
100
Time (ms)
Figure 12. Turn On Delay
200
0
10
20
Time (ms)
Figure 13. Output Voltage Turn On Transient vs. Soft Start Capacitor
A
7/97
37
RD5
40
20
0
-20
-40
PI-2071-070297
60
40
20
0
-20
-40
-60
-60
-80
-80
25
0
25
0
50
Figure 14. Line Frequency Ripple, 115 VAC In, 20 W Output
Figure 15. Switching Frequency Ripple, 115 VAC In, 20 W Output
PI-2072-070297
Output Current (A) Output Voltage (mV)
50
Time (µs)
Time (ms)
100
0
-100
2.0
1.5
1.0
0.5
0
0
10
20
Amplitude (dBmV)
80
60
40
60
40
0
0
0.01
0.1
1
10
Frequency (MHz)
Figure 17. EMI Characteristics at 115 VAC Input.
A
7/97
80
20
20
38
VDE B Limit
(VFG243A)
100
0.01
0.1
1
10
Frequency (MHz)
Figure 18. EMI Characteristics at 230 VAC Input.
PI-2060-040197
VDE B Limit
(VFG243A)
100
PI-2061-040197
Time (ms)
Figure 16. Transient Load Response (75% to 100% of load)
Amplitude (dBmV)
Output Voltage (mV)
60
80
Output Voltage (mV)
PI-2070-070297
80
RD5
8
5
1
4
1
67 T
#30 AWG
7, 8
8T
2x #24 AWG
Triple-insulated
2
3
8T
2x #30 AWG
5, 6
PIN
1
2
3
4
5, 6
7, 8
FUNCTION
HIGH-VOLTAGE DC BUS
TOPSwitch DRAIN
PRIMARY-SIDE COMMON
VBIAS
RETURN
OUTPUT
4
CORE# - PC40 EI25-Z (TDK)
GAP FOR AL OF 145 nH/T2
BOBBIN# - BE-25-118CP (TDK)
ELECTRICAL SPECIFICATIONS
Electrical Strength
60 Hz, 1 minute,
from pins 1-4 to pins 5-8
3000 VAC
Creepage
Between pins 1-4 and pins 5-8
6.0 mm (min)
Primary Inductance
Between Pins 1-2 (All other windings open)
650 µH, ±10%
Resonant Frequency
Between Pins 1-2 (All other windings open)
700 KHz (min)
Primary Leakage Inductance
Between Pins 1-2 (Pins 5-8 shorted)
35 µH (max)
NOTE: All inductance measurements should be made at 100 kHz
PI-2054-050798
Figure 19. Electrical specification of transformer TRD5
A
7/97
39
RD5
TAPE
5
6
8
7
3
4
1
2
SECONDARY
BIAS
PRIMARY
WINDING INSTRUCTIONS
Primary (2 layers)
Start at pin 2. Wind 67 turns of #30 AWG heavy nyleze
magnet wire in two layers. Finish on Pin 1
Basic Insulation
1 layer of 10.8 mm wide polyester tape for basic insulation.
Bifilar Bias Winding
Start at Pin 4. Wind 8 turns of 2 parallel strands of
#30 AWG heavy nyleze magnet wire. Space turns evenly
across bobbin to form a single layer. Finish on Pin 3.
Basic Insulation
1 layer of 10.8 mm wide polyester tape for basic insulation.
24 V Double Bifilar
Secondary Winding
Start at Pins 7 and 8. Wind 8 bifilar turns of #24 AWG
Triple Insulated Wire. Finish on Pins 5 and 6.
Outer Insulation
3 layers of 10.8 mm wide polyester tape for insulation.
Final Assembly
Assemble and secure core halves. Impregnate
uniformly using varnish.
* Triple insulated wire sources.
P/N: T28A01TXXX-3
Rubudue Wire Company
5150 E. La Palma Avenue
Suite 108
Anaheim Hills, CA 92807
(714) 693-5512
(714) 693-5515 FAX
P/N: order by description
Furukawa Electric America, Inc.
200 Westpark Drive
Suite 190
Peachtree City, GA 30269
(770) 487-1234
(770) 487-9910 FAX
P/N: order by description
The Furukawa Electric Co., Ltd
6-1, Marunouchi 2-chome,
Chiyoda-ku, Tokyo 100, Japan
81-3-3286-3226
81-3-3286-3747 FAX
PI-2055-050798
Figure 20. Construction details of transformer TRD5.
40
A
7/97
RD5
8
5
1
4
1
67 T
#30 AWG
7, 8
8T
2x #24 AWG
2
3
8T
2x #30 AWG
5, 6
PIN
1
2
3
4
5, 6
7, 8
FUNCTION
HIGH-VOLTAGE DC BUS
TOPSwitch DRAIN
PRIMARY-SIDE COMMON
VBIAS
RETURN
OUTPUT
4
CORE# - PC40 EE22/29/6-Z (TDK)
GAP FOR AL OF 145 nH/T2
BOBBIN# - YC 2204 (Ying Chin)
ELECTRICAL SPECIFICATIONS
Electrical Strength
60 Hz, 1 minute,
from pins 1-4 to pins 5-8
3000 VAC
Creepage
Between pins 1-4 and pins 5-8
6.0 mm (min)
Primary Inductance
Between Pins 1-2 (All other windings open)
650 µH, ±10%
Resonant Frequency
Between Pins 1-2 (All other windings open)
700 KHz (min)
Primary Leakage Inductance
Between Pins 1-2 (Pins 5-8 shorted)
35 µH (max)
NOTE: All inductance measurements should be made at 100 kHz
PI-2057-050798
Figure 21. Electrical specification of transformer TRD5-1.
A
7/97
41
RD5
5, 6
7, 8
4
3
TAPE
1
2
SLEEVING
SECONDARY
BIAS
TAPE MARGINS
PRIMARY
WINDING INSTRUCTIONS
Primary Margins
Tape margins with 3 mm wide polyester tape. Match height with primary
and bias windings.
Primary Windings
Start at pin 2. Wind one layer (approximately 40 turns) of 30 AWG
heavy nyleze magnet wire from bottom (pin side) to top. Use one layer
of 12.2 mm wide polyester tape over first primary layer for basic
insulation. Continue winding remaining primary turns from top to bottom.
Finish on Pin 1. Sleeve start and finish with 24 AWG Teflon sleeving.
Basic Insulation
Bias Winding
Use 1 layer of 12.2 mm wide tape for basic insulation.
Start at Pin 4. Wind 8 bifilar turns 30 AWG heavy nyleze magnet wire
from bottom to top. Spread turns evenly across bobbin. Finish on Pin 3.
Sleeve start and finish leads with 24 AWG Teflon sleeving.
Reinforced Insulation
Use 3 layers of 18.2 mm wide polyester tape for reinforced insulation.
Secondary Windings
Tape margins with 3 mm wide polyester tape. Match height with
secondary winding.
12V Secondary Winding
Start at Pins 7 and 8. Wind 8 bifilar turns of 24 AWG heavy nyleze
magnet wire from bottom to top. Spread turns evenly across bobbin.
Finish on Pins 5 and 6. Sleeve start and finish leads with 24 AWG
Teflon sleeving.
Outer Insulation
Apply 3 layers of 18.2 mm wide polyester tape for outer insulation.
Final Assembly
Assemble and secure core halves. Impregnate uniformly with varnish.
PI-2056-050798
Figure 22. Construction details of transformer TRD5-1.
42
A
7/97
RD5
A
7/97
43
RD5
Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability.
Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it
convey any license under its patent rights or the rights of others.
PI Logo and TOPSwitch are registered trademarks of Power Integrations, Inc.
©Copyright 1998, Power Integrations, Inc. 477 N. Mathilda Avenue, Sunnyvale, CA 94086 http://www.powerint.com
WORLD HEADQUARTERS
NORTH AMERICA - WEST
Power Integrations, Inc.
477 N. Mathilda Avenue
Sunnyvale, CA 94086 USA
Main:
+1•408•523•9200
Customer Service:
Phone:
+1•408•523•9265
Fax:
+1•408•523•9365
NORTH AMERICA - EAST
& SOUTH AMERICA
Power Integrations, Inc.
Eastern Area Sales Office
1343 Canton Road, Suite C1
Marietta, GA 30066 USA
Phone:
+1•770•424•5152
Fax:
+1•770•424•6567
EUROPE & AFRICA
Power Integrations (Europe) Ltd.
Mountbatten House
Fair Acres Windsor
Berkshire SL4 4LE,
United Kingdom
Phone:
+44•(0)•1753•622•208
Fax:
+44•(0)•1753•622•209
TAIWAN
Power Integrations International
Holdings, Inc.
2F, #508, Chung Hsiao E. Rd., Sec. 5,
Taipei 105, Taiwan
Phone:
+886•2•2727•1221
Fax:
+886•2•2727•1223
KOREA
Power Integrations International
Holdings, Inc.
Rm# 402, Handuk Building,
649-4 Yeoksam-Dong, Kangnam-Gu,
Seoul, Korea
Phone:
+82•2•568•7520
Fax:
+82•2•568•7474
JAPAN
Power Integrations, K.K.
Keihin-Tatemono 1st Bldg.
12-20 Shin-Yokohama 2-Chome,
Kohoku-ku, Yokohama-shi,
Kanagawa 222, Japan
Phone:
+81•(0)•45•471•1021
Fax:
+81•(0)•45•471•3717
INDIA (Technical Support)
Innovatech
#1, 8th Main Road
Vasanthnagar
Bangalore 560052, India
Phone:
+91•80•226•6023
Fax:
+91•80•228•2191
APPLICATIONS HOTLINE
World Wide
+1•408•523•9260
44
A
7/97
APPLICATIONS FAX
World Wide
+1•408•523•9361