12W 5V Evaluation board using ICE3BR4765J

Application Note, V1.3, Aug 2010
AN-EVAL3BR4765J
12W 5.0V SMPS Evaluation Board with
CoolSETTM F3R ICE3BR4765J
Power Management & Supply
N e v e r
s t o p
t h i n k i n g .
Edition 2010-08-11
Published by Infineon Technologies Asia Pacific,
8 Kallang Sector,
349282 Singapore
© Infineon Technologies AP 2008.
All Rights Reserved.
Attention please!
The information herein is given to describe certain components and shall not be considered as a guarantee
of 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.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest
Infineon Technologies Office (www.infineon.com).
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.
12W 5V Demoboard using ICE3BR4765J on board
Revision History:
2008-06-04
Previous Version:
1.2
V1.3
Page
Subjects (major changes since last revision)
1, 5, 7
Change demo board name to EVAL3BR4765J
TM
12W 5.0V SMPS Evaluation Board with CoolSET F3R ICE3BR4765J:
License to Infineon Technologies Asia Pacific Pte Ltd
Kok Siu Kam Eric
Kyaw Zin Min
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AN-PS0014
12W 5V Demoboard using ICE3BR4765J on board
Table of Contents
Page
1
Abstract..........................................................................................................................................5
2
Evaluation Board...........................................................................................................................5
3
List of Features .............................................................................................................................6
4
Technical Specifications ..............................................................................................................6
5
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
5.13
Circuit Description ........................................................................................................................7
Introduction......................................................................................................................................7
Line Input.........................................................................................................................................7
Start up............................................................................................................................................7
Operation mode ..............................................................................................................................7
Soft start ..........................................................................................................................................7
Clamper circuit ................................................................................................................................7
Peak current control of primary current...........................................................................................7
Output Stage ...................................................................................................................................7
Feedback and regulation.................................................................................................................8
Blanking Window for Load Jump / Active Burst Mode ....................................................................8
Active Burst Mode ...........................................................................................................................8
Jitter mode.......................................................................................................................................8
Protection modes ............................................................................................................................9
6
Circuit Diagram ...........................................................................................................................10
7
7.1
7.2
PCB Layout ..................................................................................................................................11
Component side component legend .............................................................................................11
Solder side copper & component legend ......................................................................................12
8
Component List ...........................................................................................................................13
9
Transformer Construction..........................................................................................................14
10
10.1
10.2
10.3
10.4
10.5
10.6
10.7
Test Results .................................................................................................................................16
Efficiency .......................................................................................................................................16
Input Standby Power .....................................................................................................................17
Line Regulation .............................................................................................................................18
Load Regulation ............................................................................................................................18
Max. Output Power .......................................................................................................................19
ESD Test .......................................................................................................................................19
Lightning Surge Test .....................................................................................................................19
11
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
11.10
Waveforms and Scope Plots......................................................................................................20
Startup @ Low and High AC Line Input Voltage and 12W load ...................................................20
Drain Source Voltage and Current During 12W load Operation ...................................................20
Load Transient Response ( Load jump from 10% to 100% Load )...............................................21
AC Output Ripple at 12W load ......................................................................................................21
Active Burst Mode @ 0.25W load .................................................................................................22
Over load protection ( with and without extended blanking; C7 ) – auto-restart...........................23
Open loop protection-auto-restart .................................................................................................24
Auto-restart enable........................................................................................................................24
Vcc overvoltage protection- auto-restart .......................................................................................25
Frequency Jittering........................................................................................................................26
12
12.1
Appendix ......................................................................................................................................27
Slope compensation for CCM operation .......................................................................................27
13
References ...................................................................................................................................27
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
1
Abstract
This document is an engineering report of an universal input 5V 12W off line flyback converter power supply
TM13
utilizing IFX F3R CoolSET
ICE3BR4765J. The application demo board is operated in Discontinuous
Conduction Mode (DCM) and is running at 65 kHz switching frequency. It has a one output voltage with
secondary side control regulation. It is especially suitable for small power supply such as DVD player, set-top
box, game console, charger and auxiliary power of high power system, etc. The ICE3BR4765J is the latest
TM
TM
version of the CoolSET . Besides having the basic features of the F3 CoolSET such as Active Burst
Mode, propagation delay compensation, soft gate drive, auto restart protection for serious fault (Vcc over
voltage protection, Vcc under voltage protection, over temperature, over-load, open loop and short optocoupler), it also has the BiCMOS technology design, built-in soft start time, built-in and extendable blanking
time, frequency jitter feature with built-in jitter period and external auto-restart enable, etc. The particular
features needs to be stressed are the best in class low standby power and the good EMI performance.
2
Evaluation Board
Figure 1 – EVAL3BR4765J
This document contains the list of features, the power supply specification, schematic, bill of material and the
transformer construction documentation. Typical operating characteristics such as performance curve and
scope waveforms are showed at the rear of the report.
13
CoolSET
package.
TM
TM
is a trade mark of Infineon which is a PWM control IC integrated with CoolMOS
Application Note
5
in one
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12W 5V Demoboard using ICE3BR4765J on board
3
List of Features
650V avalanche rugged CoolMOS™ with built-in Startup Cell
Active Burst Mode for lowest Standby Power
Fast load jump response in Active Burst Mode
65 kHz internally fixed switching frequency
Auto Restart Protection Mode for Over-load, Open Loop, Vcc Undervoltage, Over-temperature & Vcc
Over-voltage
Built-in Soft Start
Built-in blanking window with extendable blanking time for short duration high current
External auto-restart enable
Max Duty Cycle 75%
Overall tolerance of Current Limiting < ±5%
Internal PWM Leading Edge Blanking
BiCMOS technology provides wide VCC range
Built-in Frequency jitter feature and soft driving for low EMI
4
Technical Specifications
Input voltage
85VAC~265VAC
Input frequency
50Hz, 60Hz
Input Standby Power
< 40mW @ no load; < 0.7W @ 0.5W load
Output voltage and current
5V +/- 2%
Output current
2.4A
Output power
12W
Efficiency
>75% at full load
Output ripple voltage
< 50mVp-p ( exclude high frequency spike )
Application Note
6
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12W 5V Demoboard using ICE3BR4765J on board
5
Circuit Description
5.1
Introduction
The EVAL3BR4765J demoboard is a low cost off line flyback switch mode power supply ( SMPS ) using the
TM
ICE3BR4765J system IC from the CoolSET -F3R family. The circuit, shown in Figure 2, details a 5.0V, 12W
power supply that operates from an AC line input voltage range of 85Vac to 265Vac, suitable for applications
in open frame supply or enclosed adapter.
5.2
Line Input
The AC line input side comprises the input fuse F1 as over-current protection. The choke L1, X2-capacitors
C1 and Y1-capacitor C4 act as EMI suppressors. Spark gap device SG1 and SG2 can absorb high voltage
stress during lightning surge test. After the bridge rectifier BR1 and the input bulk capacitor C2, a voltage of
100 to 380 VDC is present which depends on input voltage.
5.3
Start up
Since there is a built-in startup cell in the ICE3BR4765J, there is no need for external start up resistor. The
startup cell is connecting the drain pin of the IC. Once the voltage is built up at the Drain pin of the
ICE3BR4765J, the startup cell will charge up the Vcc capacitor C5 and C6. When the Vcc voltage exceeds
the UVLO at 18V, the IC starts up. Then the Vcc voltage is bootstrapped by the auxiliary winding to sustain
the operation.
5.4
Operation mode
During operation, the Vcc pin is supplied via a separate transformer winding with associated rectification D2
and buffering C5, C6. Resistor R2 is used for current limiting. In order not to exceed the maximum voltage at
Vcc pin, an external zener diode ZD1 and resistor R3 are added.
5.5
Soft start
The Soft-Start is a built-in function and is set at 20ms.
5.6
Clamper circuit
The circuit R1, C3 and D1 clamp the DRAIN voltage spike caused by transformer leakage inductance to a
14
safe value below the drain source break down voltage VDSBR = 650V maximum.
5.7
Peak current control of primary current
TM
The CoolMOS drain source current is sensed via external shunt resistors R4 and R4A. An accurate value
of the shunt improves the peak power limitation shown in the curve peak power limitation in the rear of this
report.
5.8
Output Stage
On the secondary side the power is coupled out by a schottky diode D21. The capacitor C21 provides energy
buffering following with the LC filter L21 and C22 to reduce the output voltage ripple considerably. Storage
14
VDSBR = 650V @ Tj = 110°C
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
capacitor C21 is selected to have an internal resistance as small as possible (ESR) to minimize the output
voltage ripple. The Common mode choke L2 can suppress ESD stress from output.
5.9
Feedback and regulation
The output voltage is controlled using a TL431 (IC3). This device incorporates the voltage reference as well
as the error amplifier and a driver stage. Compensation network Cc1, Cc2, Rc1, Rc2, Rc4 constitutes the
external circuitry of the error amplifier of IC3. This circuitry allows the feedback to be precisely matched to
dynamically varying load conditions and provides stable control. The maximum current through the
optocoupler diode and the voltage reference is set by using resistors Rc5 and Rc6. Optocoupler IC2 is used
for floating transmission of the control signal to the “Feedback” input via capacitor C8 of the ICE3BR4765J
control device. The optocoupler used meets DIN VDE 884 requirements for a wider creepage distance.
5.10
Blanking Window for Load Jump / Active Burst Mode
In case of Load Jumps the Controller provides a Blanking Window before activating the Over-Load
Protection and entering the Auto Restart Mode. The blanking time is built-in at 20ms. If a longer blanking
time is required, a capacitor, C7 can be added to BA pin to extend it. The extended time can be achieved by
an internal 13uA constant current at BA pin to charge C7 from 0.9V to 4.0V. Thus the overall blanking time is
the addition of 20ms and the extended time. The voltage at Feedback pin can rise above 4V without
switching off due to Over-load Protection within this blanking time frame. During the operation the transferred
power is limited to the maximum peak current defined by the value of the current sense resistor, R4 and
R4A.
The blanking time to enter the Active Burst Mode is built-in at 20ms with no extension. If a low load condition
is detected when VFB is falling below 1.35V, the system will only enter Active Burst Mode after 20ms blanking
time while VFB is still below 1.35V.
5.11
Active Burst Mode
At light load condition, the SMPS enters into Active Burst Mode. At this start, the controller is always active
and thus the VCC must always be kept above the switch off threshold VCCoff ≥ 10.5V. During active burst
mode, the efficiency increases significantly and at the same time it supports low ripple on VOUT and fast
response on load jump. When the voltage level at FB falls below 1.35V, the internal blanking timer starts to
count. When it reaches the built-in 20ms blanking time, it will enter Active Burst Mode. The Blanking Window
is generated to avoid sudden entering of Burst Mode due to load jump.
During Active Burst Mode the current sense voltage limit is reduced from 1V to 0.34V so as to reduce the
conduction losses and audible noise. All the internal circuits are switched off except the reference and bias
voltages to reduce the total VCC current consumption to below 0.45mA. At burst mode, the FB voltage is
changing like a sawtooth between 3.0 and 3.5V. To leave Burst Mode, FB voltage must exceed 4V. It will
reset the Active Burst Mode and turn the SMPS into Normal Operating Mode. Maximum current can then be
provided to stabilize VOUT.
5.12
Jitter mode
The ICE3B4765J has frequency jittering feature to reduce the EMI noise. The jitter frequency is internally set
at 65kHz (+/-2.6kHz) and the jitter period is set at 4ms.
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
5.13
Protection modes
Protection is one of the major factors to determine whether the system is safe and robust. Therefore
sufficient protection is necessary. ICE3BR4765J provides all the necessary protections to ensure the system
is operating safely. The protections include Vcc over-voltage, over-temperature, over-load, open loop, Vcc
under-voltage, short opto-coupler, etc. When those faults are found, the system will go into auto-restart
which means the system will stop for a short period of time and re-start again. If the fault persists, the system
will stop again. It is then until the fault is removed, the system resumes to normal operation. A list of
protections and the failure conditions are showed in the below table.
Protection function
Failure condition
Vcc Over-voltage
1. Vcc > 25.5V or
2. Vcc > 20.5V & FB > 4.0V & during soft start period
Auto Restart
Over-temperature
(controller junction)
TJ > 130°C
Auto Restart
Over-load / Open loop
VFB > 4.0V and VBA > 4.0V
(Blanking time counted from charging VBA from 0.9V to
4.0V )
Auto Restart
Vcc Under-voltage / short
Opto-coupler
Vcc < 10.5V
Auto Restart
Auto-restart enable
VBA < 0.33V
Auto Restart
Application Note
Protection Mode
9
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6
Circuit Diagram
C4
1nF/250V,Y1
C23 *
BR1
+
*SG 1
F1
2KBB80R
L
85V - 265Vac
3.15A
C2
47uF/400V
C1
0.1uF/275V
L1
R1
150k/2W
EMI
5
L21
1.5uH
D21
SB540
6
C3
2.2nF/400V
L2
3
2 x 47mH, 0.4A
D1
UF4005
N
R21 *
C21
1800uF/25V
4
C22
220uF/25V
+
+
5V/2.4A
C13
0.1uF/50V
9
COM
*SG 2
R4
1.5R
2
R4A
15R
C5 22uF/50V
C7
10nF
4
1
5
+
3
D2
IC1
ICE3BR4765J
BA
GND FB
8
1
DRAIN
CS
R2
220R
1N4148
TR1 830uH
Vcc
2
7
C8
1nF
4
1
3
2
R3
39R
C6
0.1uF
Rc6
470R
Rc5
2.2K
Rc1
10k
Cc2
1nF
Cc1
1uF
Rc4
6.8k
IC2
SFH617A-3
IC3
TL431
ZD1
24V
Rc2
0R
Rc3A
*
Rc3
10k
12W 5V SMPS Demoboard with ICE3BR4765J(V0.3)
Eric Kok, Kyaw Zin Min / 1 June 2009
Figure 2 – 12W 5.0V ICE3BR4765J power supply Schemetic
TM
N.B. : In order to get the optimized performance of the CoolSET , the grounding of the PCB layout must be
connected very carfefully. From the circuit diagram above, it indicates that the grounding for the
TM
CoolSET can be split into several groups; signal ground, Vcc ground, Current sense resistor ground
and EMI return ground. All the split grounds should be connected to the bulk capacitor ground
separately.
TM
•
Signal ground includes all small signal grounds connecting to the CoolSET
filter capacitor ground, C6, C7, C8 and opto-coupler ground.
•
Vcc ground includes the Vcc capctior ground, C5 and the auxiliary winding ground, pin 2 of the
power transformer.
•
Current Sense resistor ground includes current sense resistor R4 and R4A.
•
EMI return ground includes Y capacitor, C4.
Application Note
10
GND pin such as
2010-08-11
12W 5V Demoboard using ICE3BR4765J on board
7
PCB Layout
7.1
Component side component legend
Figure 3 – Component side Component Legend – View from Component Side
Application Note
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7.2
Solder side copper & component legend
Figure 4 – Solder side copper – View from Component Side
Figure 5 – Solder side component Legend – View from Component Side
Application Note
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8
Component List
Items
Part
Type
Manufacturer / Part No.
1
BR1
2KBB80R
2
C1
0.1uF/275V, X2 capacitor
EPCOS / B32922C3104M
3
C2
47uF/400V
EPCOS / B43504A9476M
4
C3
2n2F/400V
EPCOS / B32560J8222M
5
C4
1nF/250V, Y1 capacitor
6
C5
22u/50V
Murata
7
C6
0.1u/50V
Murata
8
C7
10n/50V
Murata
EPCOS / B41851A6226M
9
C8
1nF/50V
Murata
10
C13
0.1u/50V
Murata
11
C21
1800uF/25V
12
C22
220uF/25V
13
Cc1
1uF/50V
Murata
14
Cc2
1nF/50V
Murata
15
D1
UF4005
16
D2
1N4148
17
D21
SB540
18
F1
3.15A 250V
19
IC1
ICE3BR4765J (IFX)
20
IC2
SFH617A-3
21
IC3
TL431CLP
22
J1, J2, J3, J4, J5
Jumper
23
L1
2 x 47mH, 0.4A
24
L2
2 x 100µH,(µi=10000,T38,R 6.30) (EPCOS)
25
L21
1.5uH
26
PCB
V0.2
27
R1
150K, 2W, 5%
28
R2
220R, 5%( 0805 SMD )
ROHM
29
R3
39R, 5% ( 0805 SMD )
ROHM
Infineon
Vishay
EPCOS / B82731R2401A30
NEC-Tokin
30
R4
1.5R, 0.5W, 1%
31
R4A
15R, 0.1W, 1% ( 0805 SMD )
32
Rc1
10K, 0.25W, 1%
33
Rc2
0R
34
Rc3
10K, 0.25W, 1%
35
Rc4
6.8K, 0.25W, 5%
ROHM
36
Rc5
2.2K, 0.25W, 5%
37
Rc6
470R, 0.25W, 5%
38
TR1
EF20, N87, Lp=830uH (EPCOS)
39
ZD1
24V zener diode
40
SG1*15
DSP-301N-S008
Mitsubishi
41
SG2 *16
DSP-301N-S008
Mitsubishi
EPCOS / B66206A1110T001
*15/16 Option Component
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
9
Transformer Construction
Core: EF20/10/6, N87
Bobbin: Horizontal Version
Primary Inductance, Lp : 0.83mH ( +/-2% ) measured between pin 4 and pin 5 (Gapped to Inductance)
Transformer structure :
Figure 6 – Transformer structure
Figure 7 – Transformer complete – top view
Application Note
14
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12W 5V Demoboard using ICE3BR4765J on board
Wire size requirement :
Application Note
15
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10
Test Results
10.1
Efficiency
Efficiency versus AC Line Input Voltage
90
Efficiency [ % ]
85
80
75
70
65
60
50
100
150
200
250
300
AC Line Input Voltage [ Vac ]
Efficiency @ 12W output Power
Figure 8 – Efficiency Vs. AC Line Input Voltage
Efficiency versus Output Pow er
Efficiency [ % ]
85
80
75
70
65
60
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Output Pow er [ W ]
Vin=85VAc
Vin=265VAc
Figure 9 – Efficiency Vs. Output Power @ Low and High Line 50Hz
Application Note
16
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12W 5V Demoboard using ICE3BR4765J on board
10.2
Input Standby Power
Stanby Power @ no-load versus AC Line Input Voltage
Input Power [ mW ]
30
25
20
15
10
5
0
50
100
150
200
250
300
AC Line Input Power [ Vac ]
Po = 0W
Figure 10 – Input Standby Power @ no load Vs. AC Line Input Voltage ( measured by Yokogawa
WT210 power meter - integration mode )
Standby Power @0.3W & 0.5W load vs AC Line Input voltage
0.75
0.7
Input Power [ W ]
0.65
0.6
0.55
0.5
0.45
0.4
0.35
0.3
50
100
150
200
AC Line Input Voltage [ Vac ]
Po=0.5W
250
300
Po=0.3W
Figure 11 – Input Standby Power @ 0.3W & 0.5W Vs. AC Line Input Voltage ( measured by Yokogawa
WT210 power meter - integration mode )
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
10.3
Line Regulation
Line Regulation : Vo versus AC Line Input Voltage @ 12W load
5.2
Output Voltage [ V ]
5
4.8
4.6
4.4
4.2
4
50
100
150
200
250
300
AC Line Input Voltage [ Vac ]
Vo
Figure 12 – Line Regulation Vo vs. AC Line Input Voltage
10.4
Load Regulation
Load Regulation: Vout versus Load @ Vin = 230Vac
Ouput Voltage [ V ]
5.20
5.00
4.80
4.60
4.40
4.20
4.00
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Output Power [ W ]
Output Voltage
Figure 13 – Load Regulation Vo Vs. Output Power
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
10.5
Max. Output Power
Max. Overload Output Power ( Peak Power ) versus AC Line Input Voltage
16
Max. Overload Output Power [ W ]
15.8
15.6
15.4
15.2
15
14.8
14.6
14.4
14.2
14
50
100
150
200
250
300
AC Line Input Voltage [ V ]
Peak Output Power
Figure 14 – Max. Output Power ( before over-load protection ) Vs. AC Line Input Voltage
10.6
ESD Test
Pass EN61000-4-2 Level 4: 8kV for contact discharge
10.7
Lightning Surge Test
Pass EN61000-4-5 Level 3: 1kV for line to line and 2kV for line to earth
*Adding SG1 & SG2 can pass EN61000-4-5 Level 4: 4kV for line to earth
Application Note
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11
Waveforms and Scope Plots
All waveforms and scope plots were recorded with a LeCroy 6050 oscilloscope
11.1
Startup @ Low and High AC Line Input Voltage and 12W load
Channel 1; C1 : Supply Voltage ( VCC )
Channel 2; C2 : Feedback Voltage ( VFB )
Channel 3; C3 : Drain Source Voltage ( VDS )
Channel 4; C4 : Current Sense Voltage ( VCS )
Startup time = 0.52s, Soft start time = 18ms
Figure 15 – Startup @ Vin=85Vac and 12W load
11.2
Channel 1; C1 : Supply Voltage ( VCC )
Channel 2; C2 : Feedback Voltage ( VFB )
Channel 3; C3 : Drain Source Voltage ( VDS )
Channel 4; C4 : Current Sense Voltage ( VCS )
Startup time = 0.52s, Soft start time = 18ms
Figure 16 – Startup @ Vin=85Vac and 12W load
Drain Source Voltage and Current During 12W load Operation
Channel 1; C1 : Drain Current ( IDS )
Channel 2; C2 : Drain Source Voltage ( VDS )
Duty cycle = 36.42%
Figure 17 – Operation @ Vin = 85Vac and 12W load
Application Note
Channel 1; C1 : Drain Current ( IDS )
Channel 2; C2 : Drain Source Voltage ( VDS )
Duty cycle = 11.73%
Figure 18 – Operation @ Vin = 85Vac and 12W
load
20
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12W 5V Demoboard using ICE3BR4765J on board
11.3
Load Transient Response ( Load jump from 10% to 100% Load )
Channel 1; C1 : Output Current ( Io )
Channel 2; C2 : Output Voltage ( Vo )
Current step slew rate = 0.4A/us
Figure 19 – Loadjump @ Vin=85Vac from 1.2W to
12W load
11.4
Channel 1; C1 : Output Current ( Io )
Channel 2; C2 : Output Voltage ( Vo )
Current step slew rate = 0.4A/us
Figure 20 – Loadjump @ Vin=265Vac from 1.2W to
12W load
AC Output Ripple at 12W load
Channel 2; C2 : Output Ripple Voltage ( Vo_ripple )
Vo_ripple =+/-10mV(exclude high frequency ripple)
Terminal with decoupling capacitor of 0.1uF +1uF
Figure 21 – AC output ripple @ Vin=85Vac and
12W load
Application Note
Channel 2; C2 : Output Ripple Voltage ( Vo_ripple )
Vo_ripple =+/-10mV(exclude high frequency ripple)
Terminal with decoupling capacitor of 0.1uF +1uF
Figure 22 – AC output ripple @ Vin=265Vac and
12W load
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12W 5V Demoboard using ICE3BR4765J on board
11.5
Active Burst Mode @ 0.25W load
Channel 1; C1 : Drain Source Voltage ( VDS )
Channel 2; C2 : Feedback voltage ( VFB )
Channel 3; C3 : Current Sense Voltage ( VCS )
Blanking time to enter burst mode : 17.4ms
Figure 23 – Active burst mode @ Vin=85Vac and
step from 2.4A to 0.05A
Channel 1; C1 : Drain Source Voltage ( VDS )
Channel 2; C2 : Feedback voltage ( VFB )
Channel 3; C3 : Current Sense Voltage ( VCS )
Blanking time to enter burst mode : 17.6ms
Figure 24 – Active burst mode @ Vin=265Vac
and step from 2.4A to 0.05A
Channel 4; C4 : Output Voltage ( Vo )
Output ripple : app. 50mV
Figure 25 – Output ripple at active burst mode @
Vin=85Vac and 0.25W load
Channel 4; C4 : Output Voltage ( Vo )
Output ripple : app. 50mV
Figure 26 – Output ripple at active burst mode @
Vin=265Vac and 0.25W load
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
11.6
Over load protection ( with and without extended blanking; C7 ) – autorestart
Channel 1; C1 : Output Voltage ( Vo )
Channel 2; C2 : Output current ( Io )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 18ms
Figure 27 – Over load protection without extended blanking
Channel 1; C1 : Output Voltage ( Vo )
Channel 2; C2 : Output current ( Io )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 18ms
Figure 28 – Over load protection without extended blanking
time;C7=100pF @ Vin=85Vac and output power step from 2.4A
to 4A load
Time;C7=100pF @ Vin=265Vac and output power step from
2.4A to 4A load
Channel 1; C1 : Output Voltage ( Vo )
Channel 2; C2 : Output current ( Io )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 72ms
Figure 29 – Over load protection with extended blanking
Channel 1; C1 : Output Voltage ( Vo )
Channel 2; C2 : Output current ( Io )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 72ms
Figure 30 – Over load protection with extended blanking
time;C7 = 220nF @ Vin=85Vac and output power step from 2.4A
to 4A load
time; C7 = 220nF @ Vin=265Vac and output power step from
2.4A to 4A load
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
11.7
Open loop protection-auto-restart
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Output Voltage ( Vo )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 20ms;
System enters auto-restart when VFB>4V, VBA > 4V
with defined blanking time.
Figure 31 – Open loop protection @ Vin=85Vac; Rc1
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Output Voltage ( Vo )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
Blanking time to enter auto-restart mode : 19.8ms;
System enters auto-restart when VFB>4V, VBA >
4V with defined blanking time.
Figure 32 – Open loop protection @ Vin=265Vac; Rc1
disconnected during test
disconnected during test
11.8
Auto-restart enable
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VBA< 0.33V
Figure 33 – Auto restart by trigger BA pin @ Vin=85Vac;
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VBA< 0.33V
Figure 34 – Auto restart by trigger BA pin @ Vin=265Vac;
adding 10kΩ resistor at BA pin after system start up.
adding 10kΩ resistor at BA pin after system start up.
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
11.9
Vcc overvoltage protection- auto-restart
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VCC>20.5V &
VFB >4V during soft start period
Figure 35 – Vcc overvoltage protection @
Vin=85Vac; Rc1 disconnected at startup with light
load
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VCC>20.5V
& VFB >4V during soft start period
Figure 36 – Vcc overvoltage protection @
Vin=265Vac; Rc1 disconnected at startup with light
load
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VCC>25.5V
Figure 37 – Vcc overvoltage protection @
Vin=85Vac; Rc1 disconnected after startup time with
light load
Channel 1; C1 : Drain Source voltage ( VDS )
Channel 2; C2 : Supple voltage ( VCC )
Channel 3; C3 : Feedback Voltage ( VFB )
Channel 4; C4 : BA voltage ( VBA )
System enters auto restart mode when VCC>25.5V
Figure 38 – Vcc overvoltage protection @
Vin=265Vac; Rc1 disconnected after startup time
with light load
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
11.10
Frequency Jittering
Channel 1; C1 : Drain Source voltage ( VDS )
Frequency changing from 68.7kHz ~ 73kHz, Jitter
period is set at 4ms internally ( taken from untrimmed
sample )
Figure 39 – Frequency change shown at VDS @ Vin=85Vac
Channel 1; C1 : Drain Source voltage ( VDS )
Frequency changing from 68.7kHz ~ 73kHz, Jitter
period is set at 4ms internally ( taken from
untrimmed sample )
Figure 40 – Frequency change shown at VDS @
and 12W Load
Vin=265Vac and 12W Load
Application Note
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12W 5V Demoboard using ICE3BR4765J on board
12
Appendix
12.1
Slope compensation for CCM operation
This demo board is designed in Discontinuous Conduction Mode ( DCM ) operation. If the application is
designed in Continuous Conduction Mode ( CCM ) operation where the maximum duty cycle exceeds the
50% threshold, it needs to add the slope compensation network. Otherwise, the circuitry will be unstable. In
this case, three more components ( 2 ceramic capacitors C17 / C18 and one resistor R19) is needed to add
as shown in the circuit diagram below.
Figure 41 – Circuit Diagram Switch Mode Power Supply with Slope Compensation
More information regarding how to calculate the additional components, see application note
AN_SMPS_ICE2xXXX – available on the internet: www.infineon.com (directory : Home > Power
Semiconductors > Integrated Power ICs > CoolSET® F2)
13
References
[1]
Infineon Technologies, Datasheet “CoolSET™-F3R ICE3BR4765J Off-Line SMPS Current Mode
Controller with Integrated 650V Startup Cell / Depletion CoolMOS™ ( Frequency Jitter Mode ) in DIP-8”
[2]
Eric Kok Siu Kam, Kyaw Zin Min, Infineon Technologies, Application Note “ICE3ARxx65J
TM
/ICE3BRxx65J CoolSET F3R Jitter version Design Guide”
[3]
Harald Zoellinger, Rainer Kling, Infineon Technologies, Application Note “AN-SMPS-ICE2xXXX-1,
TM
CoolSET ICE2xXXXX for Off-Line Switching Mode Power supply (SMPS )”
Application Note
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