Application Note, V1.0, Dec 2011 AN-EVAL3BR1765JZ 20W 5V SMPS Evaluation Board with CoolSET® F3R ICE3BR1765JZ Power Management & Supply N e v e r s t o p t h i n k i n g . Published by Infineon Technologies AG 81726 Munich, Germany © 2011 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the 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 the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only 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. 20W 5V Demo board using ICE3BR1765JZ Revision History: Previous Version: Page 2011-12 none Subjects (major changes since last revision) 20W 5V SMPS Evaluation Board with CoolSET® F3R ICE3BR1765JZ: License to Infineon Technologies Asia Pacific Pte Ltd Kyaw Zin Min Kok Siu Kam Eric We Listen to Your Comments Any information within this document that you feel is wrong, unclear or missing at all? Your feedback will help us to continuously improve the quality of this document. Please send your proposal (including a reference to this document) to: [email protected] V1.0 AN-PS0058 20W 5V Demo board using ICE3BR1765JZ 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 RCD clamper circuit ........................................................................................................................ 7 Peak current control of primary current........................................................................................... 7 Output stage .................................................................................................................................... 8 Feedback and regulation................................................................................................................. 8 Blanking window for load jump........................................................................................................ 8 Active burst mode ........................................................................................................................... 8 Jitter mode....................................................................................................................................... 8 Protection modes ............................................................................................................................ 9 6 Circuit diagram ............................................................................................................................ 10 7 7.1 7.2 PCB layout ................................................................................................................................... 12 Top side......................................................................................................................................... 12 Bottom side ................................................................................................................................... 12 8 Component list ............................................................................................................................ 13 9 Transformer construction .......................................................................................................... 14 10 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 Test results .................................................................................................................................. 15 Efficiency ....................................................................................................................................... 15 Input standby power ...................................................................................................................... 16 Line regulation ............................................................................................................................... 17 Load regulation ............................................................................................................................. 17 Maximum input power ................................................................................................................... 18 ESD test ........................................................................................................................................ 18 Lightning surge test ....................................................................................................................... 18 Conducted EMI ............................................................................................................................. 19 11 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.10 11.11 11.12 11.13 Waveforms and scope plots ...................................................................................................... 21 Start up at low and high AC line input voltage and maximum load............................................... 21 Soft start at low and high AC line input voltage and maximum load ............................................. 21 Frequency jittering ......................................................................................................................... 22 Drain to source voltage and current @ maximum load................................................................. 22 Load transient response ( Dynamic load from 10% to 100%) ...................................................... 23 Output ripple voltage at maximum load ........................................................................................23 Output ripple voltage during burst mode at 1 W load ................................................................... 24 Entering active burst mode ........................................................................................................... 24 Vcc overvoltage protection ............................................................................................................ 25 Over load protection (built-in + extended blanking time) .............................................................. 25 Open loop protection ..................................................................................................................... 26 VCC under voltage/Short optocoupler protection ........................................................................... 26 Auto restart enable ........................................................................................................................ 27 12 12.1 Appendix ...................................................................................................................................... 28 Slope compensation for CCM operation ....................................................................................... 28 13 References ................................................................................................................................... 28 Application Note 4 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 1 Abstract This document is an engineering report of a universal input 5V 20W off-line flyback converter power supply utilizing IFX F3R CoolSET® ICE3BR1765JZ. 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 ICE3BR1765JZ is the latest version of the CoolSET®. Besides having the basic features of the F3R 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 – EVAL3BR1765JZ 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. Application Note 5 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 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 Overload, Open Loop, Vcc Undervoltage, Overtemperature & Vcc Overvoltage Built-in Soft Start Built-in blanking window with extendable blanking time for short duration high current External auto-restart enable pin 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 60Hz, 50Hz Input Standby Power < 50mW at no load Output voltage 5V +/- 1% Output current 4A Output power 20W Active mode average efficiency(25%,50%,75% & 100%load) >79% Output ripple voltage < 50mVp-p Application Note 6 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 5 Circuit description 5.1 Introduction The EVAL3BR1765JZ demo board is a low cost off line flyback switch mode power supply ( SMPS ) using the ICE3BR1765JZ integrated power IC from the CoolSET® -F3R family. The circuit, shown in Figure 2, details a 5V, 20W 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 L11, X-capacitor C11 and Y-capacitor C12 act as EMI suppressors. Optional surge absorber device SA1, SA2 and varistor VAR can absorb high voltage stress during lightning surge test. A rectified DC voltage (120V ~ 374V) is obtained through the bridge rectifier BR1 and the input bulk capacitor C13. 5.3 Start up Since there is a built-in startup cell in the ICE3BR1765JZ, there is no need for external start up resistors. The startup cell is connecting the drain pin of the IC. Once the voltage is built up at the Drain pin of the ICE3BR1765JZ, the startup cell will charge up the Vcc capacitor C16 and C17. 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 D12 and buffering C16, C17. Resistor R12 is used for current limiting. In order not to exceed the maximum voltage at Vcc pin, an external zener diode ZD11 and resistor R13 can be added. 5.5 Soft start The Soft-Start is a built-in function and is set at 20ms. 5.6 RCD clamper circuit While turns off the CoolMOS®, the clamper circuit R11, C15 and D11 absorbs the current caused by transformer leakage inductance once the voltage exceeds clamp capacitor voltage. Finally drain-source voltage of CoolMOS® is lower than maximum break down voltage of CoolMOS®. 5.7 Peak current control of primary current The CoolMOS® drain source current is sensed via external shunt resistors R14 and R15 which determine the tolerance of the current limit control. Since ICE3BR1765JZ is a current mode controller, it would have a cycle-by-cycle primary current and feedback voltage control and can make sure the maximum power of the converter is controlled in every switching cycle. Besides, the patented propagation delay compensation is implemented to ensure the maximum input power can be controlled in an even tighter manner throughout the wide range input voltage. The demo board shows approximately +/-2.07% (refer to Figure 12). Application Note 7 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 5.8 Output stage On the secondary side the power is coupled out by a schottky diode D21. The capacitor C22 provides energy buffering following with the LC filter L21 and C23 to reduce the output voltage ripple considerably. Storage capacitor C22 is selected to have an internal resistance as small as possible (ESR) to minimize the output voltage ripple. 5.9 Feedback and regulation The output voltage is controlled using a TL431 (IC21). This device incorporates the voltage reference as well as the error amplifier and a driver stage. Compensation network C25, C26, R24, R25, R26, R27 and R28 constitutes the external circuitry of the error amplifier of IC21. 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 R22 and R23. Optocoupler IC12 is used for floating transmission of the control signal to the “Feedback” input via capacitor C18 of the ICE3BR1765JZ control device. The optocoupler used meets DIN VDE 884 requirements for a wider creepage distance. 5.10 Blanking window for load jump 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, C19 can be added to BA pin to extend it. The extended time can be achieved by an internal 13µA constant current at BA pin to charge C19 ( CBK =8.2nF) 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 4.3V 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, R14 and R15. Tblanking = Basic + Extended = 20ms + 5.11 ( 4.0 − 0.9) * CBK = 20ms + 238461.5 * CBK = 21.95ms IBK 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 1.03V 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 saw tooth between 3 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 ICE3BR1765JZ has frequency jittering feature to reduce the EMI noise. The jitter frequency is internally set at 65 kHz (+/- 2.6 kHz) and the jitter period is set at 4ms. Application Note 8 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 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. ICE3BR1765JZ provides all the necessary protections to ensure the system is operating safely. The protections include Vcc overvoltage, overtemperature, overload, open loop, Vcc undervoltage, short optocoupler, 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 restart 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 Overvoltage 1. Vcc > 20.5V & FB > 4.0V & during soft start period 2. Vcc > 25.5V Auto Restart Overtemperature (controller junction) TJ > 130°C Auto Restart Overload / Open loop VFB > 4.0V and VBA > 4.0V (Blanking time counted from charging VBA from 0.9V to 4.0V ) Auto Restart Vcc Undervoltage / Short Optocoupler Vcc < 10.5V Auto Restart Auto-restart enable VBA < 0.33V Auto Restart Application Note Protection Mode 9 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 6 Circuit diagram Figure 2 – 20W 5V ICE3BR1765JZ power supply schematic Application Note 10 2011-12-01 20W 5V Demo board using ICE3BR1765JZ N.B. : In order to get the optimized performance of the CoolSET®, the grounding of the PCB layout must be connected very carefully. From the circuit diagram above, it indicates that the grounding for the 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. • Signal ground includes all small signal grounds connecting to the CoolSET® GND pin such as filter capacitor ground, C17, C18, C19 and opto-coupler ground. • Vcc ground includes the Vcc capacitor ground, C16 and the auxiliary winding ground, pin 2 of the power transformer. • Current Sense resistor ground includes current sense resistor R14 and R15. • EMI return ground includes Y capacitor, C12. Application Note 11 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 7 PCB layout 7.1 Top side Figure 3 – Top side component legend 7.2 Bottom side Figure 4 – Bottom side copper Application Note 12 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 8 Component list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Designator Component description BR1 C11 C12 C13 C15 C16 C17 C18,C26 C19 C22 C23 C25 D11 D12 D21 F1 HS1 IC11 IC12 IC21 J1,J2,J3,J4,R16, R27,L22 L N, +5V Com L11 L21 PCB R11 R12 R13 R14 R15 R22 R23 R24 R26, R28 TR1 ZD11 DF06M (600V,1A) 0.22uF/305V 2.2nF/250V,Y1 68uF/400V 2.2nF/400V 22uF/35V 0.1uF 1nF 8.2nF/50V 2200uF/10V 1000uF/10V 330nF/50V UF4005(600V/1A) 1N485B (200V,0.2A) STPS30L45CFP 1A/250V Heat sink ICE3BR1765JZ SFH617A-3 TL431 Application Note Part number Manufacturer B32922C3224K000 DE1E3KX222MA4BL01 B43504A5826M000 EPCOS MURATA EPCOS RPER71H104K2K1A03B RPE5C1H102J2K1A03B MURATA MURATA UF4005 VISHAY ICE3BR1765JZ INFINEON B82732R2901B30 EPCOS B662061110T001 EPCOS Jumper Connector 2 x 27mH, 0.9A 1.5uH/6.3A ICE3BR1765JZ(V0.4)20W 5V 39k (2W, 5%) 18R 47R 1R (0.5W,1%) 10R (0.5W,1%) 68R 1.2k 1k 10k 725µH (80:6:18),E20/10/6(N87) 22V/0.5W 13 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 9 Transformer construction Core and material: E20/10/6, N87(EPCOS) Bobbin: Horizontal version Primary Inductance, Lp=725μH(±5%), measured between pin 4 and pin 5(Gapped to Inductance) Transformer structure: 5 6 3 4 7 2 1 Figure 5 – Transformer structure and top view of transformer complete Wire size requirement: Start Application Note Stop No. of turns Wire size Layer 1 5 7 3 6 40 6 1XAWG#30 2XAWG#26 /2 Primary Secondary 3 4 40 1XAWG#30 1 2 1 18 1XAWG#30 14 /2 Primary Auxiliary 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 10 Test results 10.1 Efficiency Figure 6 – Efficiency Vs. AC line input voltage Figure 7 – Efficiency Vs. output power @ low and high Line Application Note 15 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 10.2 Input standby power Figure 8 – Input standby power @ no load Vs. AC line input voltage ( measured by Yokogawa WT210 power meter - integration mode ) Figure 9 – Input standby power @ 0.5W, 1W, 2W & 3W Vs. AC line input voltage ( measured by Yokogawa WT210 power meter - integration mode ) Application Note 16 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 10.3 Line regulation Figure 10 – Line regulation Vout @ full load vs. AC line input voltage 10.4 Load regulation Figure 11 – Load regulation Vout vs. output power Application Note 17 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 10.5 Maximum input power Figure 12 – Maximum input power ( before overload protection ) vs. AC line input voltage 10.6 ESD test Pass (EN61000-4-2): 8kV for contact discharge (without surge absorber device) Pass (EN61000-4-2): 14kV for contact discharge (with surge absorber device; SA1 & SA2 (DA38-102MB)) 10.7 Lightning surge test Pass (EN61000-4-5): 2kV for line to earth (without surge absorber device) Pass (EN61000-4-5): 3kV for line to earth (with surge absorber device; SA1 & SA2 (DA38-102MB)) Application Note 18 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 10.8 Conducted EMI The conducted EMI was measured by Schaffner (SMR4503) and followed the test standard of EN55022 (CISPR 22) class B. The demo board was set up at maximum load (20W) with input voltage of 115Vac and 230Vac. Figure 13 – Maximum load (20W) with 115 Vac (Line) Figure 14 – Maximum load (20W) with 115 Vac (Neutral) Application Note 19 2011-12-01 20W 5V Demo board using ICE3BR1765JZ Figure 15 – Maximum load (20W) with 230 Vac (Line) Figure 16 – Maximum load (20W) with 230 Vac (Neutral) Pass conducted EMI EN55022 (CISPR 22) class B with > 8dB margin. Application Note 20 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11 Waveforms and scope plots All waveforms and scope plots were recorded with a LeCroy 6050 oscilloscope 11.1 Start up at low and high AC line input voltage and maximum load 561ms 561ms Channel 1; C1 : Drain voltage (VDrain) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Channel 1; C1 : Drain voltage (VDrain) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Startup time = 561ms Startup time = 561ms Figure 17 – Startup @ 85Vac & max. load Figure 18 – Startup @ 265Vac & max. load 11.2 Soft start at low and high AC line input voltage and maximum load 19.23ms 19.23ms Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Soft Star time = 19.23ms(32 steps) Soft Star time = 19.23ms(32 steps) Figure 19 – Soft Start @ 85Vac & max. load Figure 20– Soft Start @ 265Vac & max. load Application Note 21 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.3 Frequency jittering 62.7kHz 62.7kHz 68.2kHz 68.2kHz Channel 2; C2 : Drain to source voltage (VDS) Channel 2; C2 : Drain to source voltage (VDS) Frequency jittering from 62.7 kHz ~ 68.2kHz Frequency jittering from 62.7 kHz ~ 68.2kHz Figure 21 – Frequency jittering @ 85Vac and max. load Figure 22 – Frequency jittering @ 265Vac and max. load 11.4 Drain to source voltage and current @ maximum load Channel 1; C1 : Drain Current ( IDS ) Channel 2; C2 : Drain Source Voltage ( VDS ) Duty cycle = 44%, VDS_peak=265.4V Figure 23 – Operation @ Vin = 85Vac and max. load Application Note Channel 1; C1 : Drain Current ( IDS ) Channel 2; C2 : Drain Source Voltage ( VDS ) Duty cycle = 12.5% VDS_peak=531V Figure 24 – Operation @ Vin = 265Vac and max. load 22 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.5 Load transient response ( Dynamic load from 10% to 100%) Channel 1; C1 : Output Current ( Io ) Channel 2; C2 : Output ripple Voltage ( Vo ) Vripple_pk_pk=262mV (Load change from10% to 100%,100Hz,0.4A/μS slew rate) Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter Figure 25 – Load transient response @ 85Vac 11.6 Channel 1; C1 : Output Current ( Io ) Channel 2; C2 : Output ripple Voltage ( Vo ) Vripple_pk_pk=266mV (Load change from10% to 100%,100Hz,0.4A/μS slew rate) Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter Figure 26 – Load transient response @ 265Vac Output ripple voltage at maximum load Channel 2; C2 : Output Ripple Voltage ( Vo_ripple ) Channel 2; C2 : Output Ripple Voltage ( Vo_ripple ) Vripple_pk_pk=15mV Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter Figure 27 – AC output ripple @ Vin=85Vac and max. load Vripple_pk_pk=17mV Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter Figure 28 – AC output ripple @ Vin=265Vac and max. load Application Note 23 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.7 Output ripple voltage during burst mode at 1 W load Channel 1; C1 : Output ripple voltage (Vo) Vripple_pk_pk=22mV Probe terminal end with decoupling capacitor 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter Channel 1; C1 : Output ripple voltage (Vo) Vripple_pk_pk = 23mV Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(Electrolytic), 20MHz filter of Figure 29 – AC output ripple @ 85Vac and 1W load 11.8 Figure 30 – AC output ripple @ 265Vac and 1W load Entering active burst mode Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Blanking time to enter burst mode : 19ms (load step down from 4A to 0.2A) Figure 31 – Active burst mode @ 85Vac Application Note Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Blanking time to enter burst mode : 19ms (load step down from 4A to 0.2A) Figure 32 – Active burst mode @ Vin=265Vac 24 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.9 Vcc overvoltage protection VCC OVP2 VCC OVP1 VCC OVP2 Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) VCC OVP2 first & follows VCC OVP1 (R28 disconnected during system operating with no load) Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) VCC OVP2 first & follows VCC OVP1 (R28 disconnected during system operating with no load) Figure 34 – Vcc overvoltage protection @ 265Vac Figure 33 – Vcc overvoltage protection @ 85Vac 11.10 VCC OVP1 Over load protection (built-in + extended blanking time) Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Over load protection with 21.9ms(20+1.9) blanking time (output load change from 4A to 5.5A, C19=10nF) Figure 37 – Over load protection with built-in+extended blanking time @ 85Vac Application Note Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Over load protection with 21.9ms(20+1.9) blanking time (output load change from 4A to 5.5A, C19=10nF) Figure 38 – Over load protection with built-in+extended blanking time @ 265Vac 25 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.11 Open loop protection Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Open loop protection (R28 disconnected during system operation at max. load) – over load protection Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Open loop protection (R28 disconnected during system operation at max. load) – over load protection Figure 39 – Open loop protection @ 85Vac Figure 40 – Open loop protection @ 265Vac 11.12 VCC under voltage/Short optocoupler protection Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) VCC under voltage/short optocoupler protection (short the transistor of optocoupler during system operating @ full load) VCC under voltage/short optocoupler protection (short the transistor of optocoupler during system operating @ full load) Figure 41 – Vcc under voltage/short optocoupler protection @ 85Vac Figure 42 – Vcc under voltage/short optocoupler protection @ 265Vac Application Note 26 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 11.13 Auto restart enable Exit autorestart Exit autorestart Enter autorestart Enter autorestart Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) Channel 1; C1 : Current sense voltage (VCS) Channel 2; C2 : Supply voltage (VCC) Channel 3; C3 : Feedback voltage (VFB) Channel 4; C4 : BA voltage (VBA) External autoreatart enable (short BA pin to Gnd by 10Ω resistor & open) External autorestart enable (short BA pin to Gnd by 10Ω resistor & open) Figure 43 – External protection enable @ 85Vac Figure 44– External protection enable @ 265Vac Application Note 27 2011-12-01 20W 5V Demo board using ICE3BR1765JZ 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 45 – 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 ICE3BR1765JZ Off-Line SMPS Current Mode Controller with Integrated 650V CoolMOS® and Startup cell ( frequency jitter Mode ) in Dip-7” [2] Kyaw Zin Min, Kok Siu Kam Eric, Infineon Technologies, Application Note “CoolSET®-F3R (DIP-8, DIP7 & DSO-16/12) new Jitter version Design Guide” [3] Harald Zoellinger, Rainer Kling, Infineon Technologies, Application Note “AN-SMPS-ICE2xXXX-1, CoolSET®. ICE2xXXXX for Off-Line Switching Mode Power supply (SMPS )” Application Note 28 2011-12-01