Design Note for Adapter Single Output 80W

Version 2.3, August 2002
Design Note
DN-EVALSF2-ICE2B765P-1
CoolSET
80W 24V Design Note for Adapter using ICE2B765P
Author:
Rainer Kling
Published by Infineon Technologies AG
http://www.infineon.com/CoolSET
Power Management & Supply
N e v e r
s t o p
t h i n k i n g
80W 24V Adapter with ICE2B765P on Board
Table of Contents
TABLE OF CONTENTS.......................................................................................................................... 1
INTRODUCTION ..................................................................................................................................... 2
Application........................................................................................................................................ 2
CoolSET ........................................................................................................................................ 2
LIST OF FEATURES .............................................................................................................................. 3
POWER SUPPLY SPECIFICATION....................................................................................................... 3
SCHEMATIC ........................................................................................................................................... 4
PCB LAYOUT ......................................................................................................................................... 5
DESCRIPTION ........................................................................................................................................ 6
Introduction....................................................................................................................................... 6
Line Input.......................................................................................................................................... 6
Startup .............................................................................................................................................. 6
Operation Mode................................................................................................................................ 6
Softstart ............................................................................................................................................ 6
Snubber Network.............................................................................................................................. 6
Limitation of primary current............................................................................................................. 6
Output Voltage ................................................................................................................................. 7
Regulation ........................................................................................................................................ 7
EMI Behavior .................................................................................................................................... 7
BILL OF MATERIAL ............................................................................................................................... 8
TRANSFORMER CONSTRUCTION DOCUMENTATION ..................................................................... 9
PERFORMANCE DATA ....................................................................................................................... 12
Efficiency ........................................................................................................................................ 12
No-Load Input Power (Standby)..................................................................................................... 13
Regulation and Power Limiting ...................................................................................................... 13
Startup Curves (Low Line) ............................................................................................................. 15
Startup Curves (High Line)............................................................................................................. 16
Loadjump........................................................................................................................................ 17
AC Output Voltage Ripple .............................................................................................................. 18
Drain Source Voltage and Current ................................................................................................. 19
REFERENCES ...................................................................................................................................... 21
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Page 1 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Introduction
Application
This document is an engineering report that describes a universal input power supply designed in a
typical off line flyback converter topology that utilizes the ICE2B765P CoolSET. The application
1
operates in discontinuous current mode using the frequency reduction during standby condition . The
board has one output voltage with secondary regulation.
This board demonstrates the basic performance features and the power capability of the latest
CoolSET device ICE2B765P of the second generation of CoolSET in a TO220 package with
extended creepage distance for higher electrical strength and isolated tab.
CoolSET
CoolSET is a current mode control IC and the power MOSFET CoolMOS within one standard
package designed for low cost power supplies. CoolSET combines the superior technology of
CoolMOS and the optimized technology of the control IC with enhanced protection features and
improved standby power concept. The integrated propagation delay compensation (patented by
Infineon Technologies) prevents a current overshoot, the result is a reduced electrical stress on the
MOSFET, the transformer and the output diode. The 650V / 800V high avalanche rugged CoolMOS
eliminates or reduces the need for a heatsink and permits a SMPS design with a simple RCD snubber
and a low cost standard transformer design. The lowest area specific Rdson leads to a high efficiency
and permits an operation at high ambient temperature. CoolSET permits always a safety operation
during any error cases due to the integrated protection features.
Figure 1– EVALSF2-ICE2B765P
This document contains the power supply specification, schematic, bill of material and the transformer
construction documentation. Typical operating characteristics are presented at the rear of the report
and consist of performance curves and scope waveforms.
Note:
Design calculations for the components and the transformer were performed in accordance with the
application note “AN–SMPS–ICE2AXXX for OFF – Line Switch Mode Power Supplies” and
FlyCal, a EXCEL based design software according to the application note AN-SMPS-ICE2AXXX. The
application note and FlyCal are available on the Internet: www.Infineon.com/CoolSET
1
POUT = 0W
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Page 2 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
List of Features
Feature
CoolSET Device ICE2B765P
External Sense
Adjustable Soft Start
Modulated Gatedrive
Over Load Protection with auto restart
Over Current Protection with auto restart
Over Temperature Shut Down with auto restart
Open Loop Protection with auto restart
Under Voltage Lock Out with auto restart
2
Drain Source Voltage 650V
Frequency Reduction
Internal Leading Edge Blanking
67 kHz operating frequency
TO220 ISODRAIN Package with isolated Tab
Standby Power according to European Commission
Table 1 – List of Features
Power Supply Specification
Description
Input Voltage
Line Regulation (85...270V)
Input Frequency
No Load Input Power (230VAC)
Output Voltage
AC Output Voltage Ripple (270VAC)
Output Current
Output Power
Peak Power
Standby Power
Total Regulation
Load Regulation (10...100%)
Efficiency (85VAC) @ nominal Load
Efficiency (270VAC) @ nominal Load
Symbol
Min
Input Section
VACIN
85
f
47
Output Section
VOUT
23.5
VRipple
IOUT
3.25
POUT
0
POUTmax
η
η
Typ
Max
Units
115/230
<1
50/60
< 0.9
270
VAC
%
Hz
W
24
<0.1
3.3
80
95
< 1.0
±2
<1
85
90
24.5
64
3.35
85
VDC
VP-P
ADC
W
W
W
%
%
%
%
Environmental
Conducted EMI
EN55022B
Ambient Temperature
TA
0
50
75
°C
Thermal Consideration @ VACIN = 85V and Dmax = 69% (∆T @ Ta = 25°C)
Transformer
40
°C
CoolSET
60
°C
Output Diode
60
°C
Output Capacitors
35
°C
Table 2 – Power Supply Specification
2
VDSBR at Tj = 110°C
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Page 3 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Schematic
Figure 2 Power Supply Schematic
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Page 4 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
PCB Layout
Figure 3 Board Layout - Component Side
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Page 5 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Description
Introduction
The EVALSF2-ICE2B765P demoboard is a low cost flyback switching power supply using the
ICE2B765P integrated circuit from the CoolSET-F2 family. The circuit shown in Figure 2 details a
24V, 80W supply that operates from an line input voltage range of 85 to 265VAC, suitable for
applications requiring either an open frame supply or an enclosed adapter.
Line Input
The AC line input side comprises of an input fuse F1 as line input over current protection as well as
choke L5 and the X2 capacitors C8 and C24 as radio interference suppressors. R19 prevents the
application against line shut on spikes. After the bridge rectifier BR1 and input capacitor C3, a voltage
from 120 to 380 VDC is present. Only a 220µF input capacitor is required due to the wider duty cycle
DCMAX of the ICE-F2-family.
Startup
From the line input voltage, the current supply which is used to charge up the chip supply capacitor C4
is derived by using resistors R7 and rectifier diode D10. Because of the very low start up current of
typically 27µA, a high-value resistor can be used to realize the startup.
Note:
Improve your standby power via increasing R7.
Operation Mode
During operation, the VCC pin is supplied via a separate transformer winding with associated
rectification D2 and buffering C4 and filter capacitor C20. Resistor R8 is used for current limiting
during the charging of C4. In order not to exceed the maximum voltage at the VCC pin an external
zener diode D7 limits this voltage. During light or no load condition the switching frequency is reduced
down to 21kHz in order to reduce the switching losses without audible noise.
Note:
In order to improve the standby power, set the board in the burst mode during no load condition via
increasing the chip supply resistor R8.
Softstart
In order to minimize the electrical stress, a Soft-Start function is realized by an internal resistor and the
adjustable external capacitor C18.
Snubber Network
Due to the high avalanche rugged CoolMOS inside, a simple RCD snubber protection can be used.
The network R10, C12 and D3 clamp the DRAIN voltage spike caused by transformer leakage
inductance to a safe value below the drain source break down voltage VDSBR = 650V maximum.
Limitation of primary current
The CoolMOS drain source current is sensed via external shunt resistors R20 and R21. An accurate
value of the shunt improves the peak power limitation shown in the curve peak power limitation in the
rear of this report and minimize the electrical stess on the MOSFET, the Transformer and the output
rectifier.
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Page 6 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Output Voltage
Power is coupled out on the secondary side via a fast-acting diodes D1 and D9 with low forward
voltage. Capacitors C5 and C29 performs energy buffering, a following LC - filter C32 and inductor L9
considerably reduces the output voltage ripple. Storage output capacitors C5 and C29 is designed to
exhibit a very low ESR in order to minimize the output voltage ripple caused by the triangular current
characteristic. The output voltage is set with resistors R1 and R2.
Regulation
The output voltage is controlled using a type TL431 reference diode. This device incorporates the
voltage reference as well as the error amplifier and a driver stage. Compensation network C1, C2, R1,
R5 constitutes the external circuitry of the error amplifier of IC2. This circuitry allows the feedback to
be precisely matched to dynamically varying load conditions, thereby providing stable control. The
maximum current through the optocoupler diode and the voltage reference is set by using resistors
R3, R4. Optocoupler IC1 is used for floating transmission of the control signal to the “Feedback” input
via resistor R9 and capacitor C6 of the ICE2B765P control device. The optocoupler used meets DIN
VDE 884 requirements for a wider creepage distance.
EMI Behavior
In order to reduce the conducted EMI behavior, capacitor C7 is set in parallel to the transformer TR1.
Note:
The value should not exceeds 2.2nF in order to guarantee a safety off line switch mode power supply
design.
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Page 7 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Bill of Material
ICE2B765P Evaluation Board 24V/ 80W
Pos. Part
Type
Number Values Note
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
BR1
C1 [nF]
C2 [nF]
C3 [µF]
C4 [µF]
C5 [µF]
C6 [nF]
C7 [nF]
C8 [µF]
C12 [nF]
C18 [nF]
C20 [nF]
C24 [µF]
C29 [µF]
C32 [µF]
B380 C5000
470
0.15
220
22
1000
2.2
2.2
0.22
4.7
330
100
0.22
1000
330
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
50V
50V
385V
25V
35V
50V
275V
275V
400V
50V
50V
275V
35V
35V
16
D1
MUR1520
1
200V
17
18
19
D2
D3
D7
1N4148
1N4937
ZPD18
1
1
1
200V
18V
20
D9
MUR1520
1
200V
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
D10
F1
F1
IC1
IC2
IC3
L9 [µH]
L5 [µH]
1N4007
Microfuse
Clip for Fuse
SFH617A-3X016
TL431CLP
ICE2B765P
1.0
2*27mH
R1 [kΩ] 40.0
R2 [kΩ] 4.7
R3 [kΩ] 1.1
R4 [kΩ] 1.6
R5 [kΩ] 180.0
R7 [kΩ] 680
7.5
R8 [Ω]
22.0
R9 [Ω]
10.0
R10 [kΩ]
R19
NTC10
R20 [Ω] 0.43
R21 [Ω] 0.39
TR1
ETD39/18/13
Heatsink
Heatsink
X1, X2
Connector 2pol.
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1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
Ordering Code
Low ESR
X7R
Y1 Cap
X2 Cap
MKT
X7R
X7R
X2 Cap
Low ESR
Low ESR
3.15A
6A
1.7A
0.6W
0.6W
0.6W
0.6W
0.6W
0.6W
0.6W
0.6W
2W
1%
1%
0.6W 1%
0.6W 1%
1mm Gap
11 k/W
18 k/W
For ICE2B756P
For Output Rectifiers
Page 8 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Transformer Construction Documentation
Al-Value:
Gap:
Margin:
Inductance:
Leakage Ind.:
190 nH
1 mm
0 mm
1,49E-04 H
7,7E-06 H (5%)
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Page 9 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
www.Infineon.com/CoolSET
Page 10 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
www.Infineon.com/CoolSET
Page 11 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Performance Data
Efficiency
Efficiency vs. Line Input Voltage
100
80W Output
95
Efficiency [%]
90
85
80
75
70
65
60
55
50
80
100
120
140
160
180
200
220
240
260
280
Input Voltage (VAC 50Hz)
Figure 4 Efficiency vs. Line Input Voltage
Efficiency vs. Output Power
100
95
85 VAC
270 VAC
Efficiency [%]
90
85
80
75
70
65
60
55
50
0
10
20
30
40
50
60
70
80
Output Power [W]
Figure 5 Efficiency vs. Output Power @ Low and High Line 50Hz
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Page 12 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
No-Load Input Power (Standby)
Standby Power versus Line Voltage @ No Load
1,1
1,0
Pout = 0W
Input Power [W]
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0
80
100
120
140
160
180
200
220
240
260
280
Input Line Voltage (VAC 50Hz)
Figure 6 Standby Power vs. Line Input Voltage and No Load Condition (Pout = 0W)
Regulation and Power Limiting
Line Regulation @ Pout = 80W
25
Output Voltage [VDC]
Iout = 3.33 A
24,5
24
23,5
23
80
100
120
140
160
180
200
220
240
260
280
Input Voltage (VAC 50Hz)
Figure 7 Regulation vs. Line Input Voltage
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Page 13 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Load Regulation
25
Output Voltage [VDC]
230 VAC
24,5
24
23,5
23
0
10
20
30
40
50
60
70
80
Output Power [W]
Figure 8 Regulation vs. Load
Maximum Output Power vs. Line Input Voltage
Maximum Output Power [W]
100
95
90
85
80
75
70
80
100
120
140
160
180
200
220
240
260
280
AC Line Input Voltage [V]
Figure 9 Peak Power (Over Current Shut Off Threshold) vs. Line Input Voltage
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Page 14 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Startup Curves (Low Line)
VCC
VSS
VFB
VOUT
Figure 10 Startup VACIN = 85V no Load Conditon (POUT = 0W)
VCC
VSS
VFB
VOUT
Figure 11 Startup @ Vacin = 85V and nominal Load (POUT = 80W)
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Page 15 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Startup Curves (High Line)
VCC
VSS
VFB
VOUT
Figure 12 Startup @ 270VACIN and no Load Condition (POUT = 0W)
VCC
VSS
VFB
VOUT
Figure 13 Startup @ Vacin = 270V and nominal Load (POUT = 80W)
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Page 16 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Loadjump
VFB
Figure 14 Loadjump form 10% up to 100% at VACIN = 85V
VFB
Figure 15 Loadjump form 10% up to 100% at VACIN = 270V
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Page 17 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
AC Output Voltage Ripple
Figure 16 AC Output Voltage Ripple @ VACIN = 85V
Figure 17 AC Output Voltage Ripple @ VACIN = 270V
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Page 18 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Drain Source Voltage and Current
VDS
VSense
Figure 18 Drain Source Voltage and Current @ VACIN = 85V
VDS
VSense
Figure 19 Drain Source Voltage and Current @ VACIN = 85V
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Page 19 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
Note:
The built-in transformer does not comply with EN60950 safety requirements
in respect of electrical isolation.
Change service
Issue status
1.0
2.1
2.2
2.3
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Changes
First issue
BOM Update
Performance Data
BOM Update
Page 20 from 22
Date
02.05.2002
02.08.2002
27.08.2002
08.11.2002
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
References
[1]
ICE2AXXX for OFF-Line Switch Mode Power Supplies
Application Note, Infineon Technologies
[2]
CoolSET -II
Off-line SMPS Current Mode Controller with High Voltage CoolMOS on Board
Datasheet, Infineon Technologies
Revision History
Application Note AN-EVALSF2-ICE2B765P-01
Actual Release: 2.3 Date: 2002-08-27
Previous Release: V1.0
Page of
actual
Rel.
--
Page of
Subjects changed since last release
prev. Rel.
--
See change service
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Page 21 from 22
EVALSF2-ICE2B765P
V2.3
80W 24V Adapter with ICE2B765P on Board
For questions on technology, delivery and prices please contact the Infineon
Technologies Offices in Germany or the Infineon Technologies Companies and
Representatives worldwide: see the address list on the last page or our webpage at
http://www.infineon.com/CoolSET
CoolMOS and CoolSET are trademarks of Infineon Technologies AG.
Edition 2002-05--02
Published by Infineon Technologies AG,
St.-Martin-Strasse 53,
D-81541 München
© Infineon Technologies AG 2000.
All Rights Reserved.
Attention please!
The information herein is given to describe certain components and shall not be considered as warranted characteristics.
Terms of delivery and rights to technical change reserved.
We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts
stated herein.
Infineon Technologies is an approved CECC manufacturer.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in
Germany or our Infineon Technologies Representatives worldwide (see address list).
Warnings
Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your
nearest Infineon Technologies Office.
Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon
Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the
safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support
and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be
endangered.
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Page 22 from 22
EVALSF2-ICE2B765P
V2.3
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