Phase Cut Dimmable Isolated Flyback Converter for PAR38 LED Lamp with ICL8002G & CoolMOS™ 600V C6 Application Note http://www.infineon.com/ledoffline Rev. 1.0, 2012 -06 -21 Power Management & Multimarket Edition June, 2012 Published by Infineon Technologies AG 81726 Munich, Germany © 2012 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. Test report 2 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Table of Contents 1 Introduction 4 2 List of Features 4 3 Technical Specification 4 4 Setup 5 4.1 Input Connection 5 4.2 Output Connection 5 5 Schematic 6 6 Test Data and Waveforms 7 6.1 Efficiency 7 6.2 Start-Up 8 6.3 Power Factor & THD 9 6.4 Power MOSFET Waveforms 10 6.5 7 Output 11 6.6 Output Current Regulation 11 6.7 LED Open Load Protection 13 6.8 Output Short Circuit Protection 14 Dimming 15 Board Layout 16 9 Bill of Materials 17 10 Transformer 20 8 11 Related Documentation Test report 21 3 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Introduction 1 The PAR38 EVAL-LED-ICL8002G is a dimmable single-stage PFC/ Fly-back LED driver designed for high efficiency, high power factor, low THD and isolation. The ICL G’s quasi-resonant operation mode, primary side control, cycle-by-cycle current control, integrated PFC and phasecut dimming control makes it an excellent choice for dimmable LED bulbs especially those requiring very high efficiency. 2 List of Features • • • • • • • • • • • High efficiency > 89% High Power Factor (>0.97) with low THD (<10%). High Dimmer compatibility. Quasi-resonant operation mode with isolated Fly-back. Primary side control with integrated PFC. Integrated Start-Up Power cell. Built-in digital soft-start Cycle-by-cycle peak current limitation VCC over- and under-voltage lockout Auto restart mode for short circuit and thermal protection Adjustable latch-off mode for output overvoltage protection 3 Technical Specification Parameter Input Voltage Line Frequency Output Voltage Output LED Current Output Power Power Factor THD Efficiency Table 1 Specification Test report Value 108-132 60 32-40 560 22 > 0.97 < 10 > 89 Unit Vrms Vdc mA W % % 4 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G 4 Setup Attention: This Evaluation board is not protected against human touch. Do not touch live board due to dangerous voltages. Do not leave board unattended when it is powered up. 4.1 Input Connection AC source is applied at the two terminals near the common mode inductor. Please refer to Figure 1 for input voltage connection and Table 1 for input voltage range. For dimming operation, the phase cut dimmer should be connected to the input terminals according to the dimmer’s instructions provided by the dimmer manufacturer. Figure 1 Top Side of PAR38 EVAL-LED-ICL8002G 4.2 Output Connection The output is functionally isolated from the AC input supply. Connect the load at the electrolytic capacitors C3 and C4. Please refer to Figure2. Please make sure not to exceed the maximum output voltage. For the output voltage range (number of LEDs in string) please refer to Table 1. Output + Output - Figure 2 Test report Bottom Side of PAR38 EVAL-LED-ICL8002G 5 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G 5 Schematic Figure 3 Schematic Test report 6 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G The ICL8002G is a quasi-resonant PWM controller that can operate in different topologies such as Buck and Fly-back converters. The PAR38 EVAL-LED-ICL8002G is designed using the Fly-back topology to provide isolation. Test Data and typical operating waveforms are shown below. See app note AN-EVALLED-ICL8002G-B2 for details on the non isolated buck topology. 6 6.1 Test data and Waveforms Efficiency The Quasi-Resonant operation of this controller o i ed ith I fi eo ’s high perfor a e Coolmos™ HV MOSFETs; results in high conversion efficiency. The chart below is taken at nominal input voltage of 120VRMS. Efficiency is dependent on output voltage. The ICL8002G IC is designed to maintain constant output power. If the number of LEDs in the string is reduced (output voltage is reduced), the LED current increases resulting in increased power loss in the output diode. This results in slight loss of efficiency which as shown in figure 4. Figure 4 Test report Efficiency vs Output Voltage 7 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G This output diode is a significant contributor to power loss overall. If additional efficiency is required, active rectification can be applied to increase efficiency by 1-2%. Figure 5 Secondary with Synchronous Rectification On the other hand, if cost is valued over efficiency, components with lower cost can be substituted for Q3, Q4 and D5. Q4 can be replaced with IPD60R950C6 which results in a 0.1% drop in efficiency. Q3 can be substituted with a lower VDS and/ or higher Rds-on MOSFET such as Infineon’s new CE 500V Vds series. Replacing Q3 with IPP60R950C6 (higher Rds-on) drops efficiency by 0.25%. Additional cost reduction can be achieved by eliminating the active damper (highlighted in green in schematic above) and substituting a 33- Ω three watt resistor in series with fuse F1. The substitution of the resistor lowers efficiency by about 3%. Other cost reductions can also be considered including changing output diode D5 or the transformer to a lower cost selection. These may also affect efficiency. 6.2 Start Up The ICL8002G integrates a start-up cell to charge Vcc capacitor (C15) in order to kick-start the controller into operation. Please refer to schematic. The integrated start-up cell allows for short start-up times of the system without sacrificing efficiency. The below waveforms were obtained with C15=10uF. If a shorter Start-up time is required, the value of C15 can be reduced. Test report 8 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Figure 6 6.3 Start-up waveform: Input voltage (CH1, Blue), Output voltage (CH2, Turquoise), and output current (CH3, Pink) Power Factor & THD The input current and voltage waveforms are shown in Figure 7 below. The input current waveform shown below is sinusoidal and in phase with the input voltage indicating low THD (Total Harmonic Distortion) and high PF (Power Factor). Measured PF and THD over the entire input voltage range are given below. Figure 7 Test report Input voltage (CH1, Blue), Input current (CH2, Turquoise). 9 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Figure 8 6.4 Power Factor & THD vs. Input Voltage Power MOSFET Waveforms Being a Quasi-Resonant PWM mode controller, the ICL8002G operates at the boundary of DCM/CCM turning on the power MOSFET (Q4) when the voltage across its Drain to Source is close to zero. This significantly reduces capacitive switching loss of the power MOSFET during turn-on. The VDS waveform displayed in Figure 9 shows a Quasi-resonant operation. The voltage waveform across sense resistors R4, R25 and R26 quantifies the current through power MOSFET Q4. Figure 9 VDS waveform of power MOSFET (CH1, Blue), Sense resistors (R4, R25 & R26) voltage (CH2, Turquoise). Test report 10 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G 6.5 Output Since the PAR38 EVAL-LED-ICL8002G is a single stage design, it produces a ripple at twice the input voltage frequency. If a smaller LED current ripple is required, larger output capacitance can be used. The output capacitance in this demo board (C3 & C4) is sized for an output current ripple which exhibits no visible light modulation. Figure 10 Output voltage waveform (CH1, Blue), Output Current (CH2, Turquoise) If the users target specification requires a different combination of output voltage and current then the existing demo board supports, minor modifications will be needed. The flyback topology can support a wide range of operation voltages and currents with changes to the transformer build and value changes for sense resistors R4, R25 and R26. I fi eo ’s Lightdesk tool can help with these changes. Please go to www.Infineon.com/Lightdesk and select AC/DC dimmable designs. Note: You will need to modify the auxiliary output voltage on the transformer to allow the use of the Vcc regulator that is included in this design. Lightdesk’s design results use a default auxiliary voltage of approximately 19V so the number of turns on the au iliar i di g ill ha e to e i reased appro i atel . ti es Lightdesk’s calculated value to provide the target 30V auxiliary voltage output at full load. 6.6 Output Current Regulation PAR38 EVAL-LED-ICL8002G mimics an incandescent light bulb with its output current changing in proportion to the input voltage variation. The output voltage and current shown below in figure 11 is for a 39V LED load. Test report 11 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Figure 11 Output Current vs. Input Voltage variations The demo board is capable of driving an output LED string with a voltage range between 32 to 40V across the output. The effect on the output current over this range of output voltages is shown in figure 12. Figure 12 Output Current vs. Output Voltage variations If the performance shown in figure 11 and 12 is not acceptable for your end application; the feed-forward circuit of figure 13 can be implemented to improve output current regulation due to output voltage and input voltage variations. The below circuit could provide a line and load regulation of less than 5% over the conditions shown in figure 11 and 12 above Test report 12 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G + Vin Rectified 10K 1.1M 510K 10K VCC 750K BC857S 300K 75K 1uF Connect right to Aux winding 2K 3.3V 0.1uF/ 50V Q4 Pin3 of IC CS 1.5K Rsense R4//R25//R26 Figure 13 Feed-forward Circuit for Output Current Regulation due to LED Vf and Line Variations. 6.7 LED Open Load Protection The ICL8002G provides protection against open loads via pin ZCV. When open load occurs (output current drops to zero), the output voltage will rise. The auxiliary bias voltage (C13) is coupled to the secondary. When the voltage at pin ZCV reaches the OVP threshold (Vzcovp=3.7V) the IC will stop switching and latches off. Power recycling of the input is required to restart the LED driver. Test report 13 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Figure 14 6.8 Output voltage (CH1, Blue), Gate of Q4 (CH2, Turquoise), Output Current (CH3, Pink) Output Short Circuit Protection In case of a short circuit at the output, the voltage at Vcc pin will drop below the under voltage threshold activating the Auto Restart mode. Figure 15 Test report Output voltage (CH1, Blue), Gate of Q4 (CH2, Turquoise), Output Current (CH3, Pink) 14 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G 7 Dimming The ICL8002 delivers a smooth dimming curve that transitions from full light output to minimum dimming as shown in Figure 16. Figure 16 Output current vs Dimmer Phase angle We have tested this evaluation board for dimming performance resulting in the list of dimmers below that exhibit no flicker or shimmer. This list of dimmers does not represent the complete list of supported dimmers; but rather a selection of commonly used and available dimmers in the North American market. Active damping, Vcc regulation, and an active bleeder (see schematic) were used in the design of the PAR38 to maximize dimming performance. If a small fixed list of dimmers, or a non dimming solution is required; then these blocks can be deleted and the passive circuits tuned to maximize the fixed dimmer list. This will result in a significantly reduced BOM count and lower cost. Test report 15 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Manufacturer LEVITON LEVITON LEVITON LEVITON LEVITON LEVITON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON LUTRON GE COOPER Table 2 Dimmer P/N CAT. NO. 6683 CAT. NO. 6684 CAT. NO. 6161 CAT. NO. IPI06-1LX CAT. NO. IPI06 6631-LW CN-600 PHW DV603PG-WH D-600P-WH LG-600PH-WH LX-600PL-WH LXLV-600PL-WH MAW-600H-WH MCU04 NF-603P-WH S-600-WH S-600P-WH S-603PG-WH TG-600 PH-WH TGLV-600PR-WH 4YPH5 5PWL6 AY-600 PNL GE 0723 COOPER 47Y Dimmer List The transformer auxiliary ratios must be changed if this board is used with a load that is less than 32V at full rated current. If less than 32V of LED load is applied without changing the auxiliary winding the solution may flicker due to loss of Vcc supply voltage. Vcc voltage is proportional to the output voltage. Please see the comments in section 6.5 regarding how to change the design to deliver different output voltages and currents. 8 Board Layout A two layer PCB with 37.4mm x 87.2mm dimensions and a thickness of 1.5mm is used for the PAR38 EVAL-LED-ICL8002G. There is sufficient creepage between primary and secondary circuits to meet class 2 insulation requirements. Test report 16 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G Figure 17 Top Side Figure 18 Bottom Side 9 Bill of Materials Component Value Manufacturer F1 MOV1 Fuse, FUSE 1.6A T-LAG IEC VARISTOR 150VRMS 10mm RADIAL CAP 0.33uF 250V METAL BELL FUSE EPCOS C1 Test report 17 EPCOS Manufacturer Part Number RST 1.6AMMO S10K150 B32521C3334J Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G C2 C3, C4 C5 C6 C7 C8 C9 C11 C12 POLY 2.2nF 630V METAL POLY CAP 220uF 50V ELECT RADIAL Y CAP CER 1500pF 1KVDC RAD CAP CER 47nF 25V X7R 20% 0603 X2 cap 33nF 305VAC X2 cap 10nF 305VAC CAP CER 47pF 50V COG 0603 CAP 0.1uF 305VAC CAP CER 1000pF 50V COG 0402 EPCOS SUNCON VISHAY MURATA EPCOS EPCOS MURATA EPCOS MURATA C13, C14 CAP CER 10uF X7S 50V 1210 TDK Corporation CAP CER 1uF 50V X7R 0805 CAP CER 220pF 50V X7R 0402 CAP CER 1000pF 50V 5% COG 0603 COMMON MODE INDUCTOR 6mH 1.5mH MURATA C15, C17 C16 C18 L1 T1 R1, R2 R3 R4 R5, R27 R6 R7 R8-R11 R13 R14 R15 R16 Test report RES 4.7KΩ 1/4W 5% 1206 SMD RES 3.01KΩ 1% 0402 SMD RES 3.01Ω 1% 0805 SMD RES 220Ω 1W 5% 2512 SMD RES 26.7KΩ 1% 0603 SMD RES 10Ω 1/8W 5% 0805 SMD RES 750KΩ, 1/8W 5% 0805 SMD RES 2MΩ 1/4W 5% 1206 SMD RES 100KΩ 1/10W 5% 0603 SMD RES 10.0KΩ 1/10W 1% 0603 SMD RES 402KΩ 1/10W 1% 0603 SMD 18 MURATA MURATA WURTH ELECTRONICS WURTH ELECTRONICS B32529C8222J 50ME220CA VY1152M41Y5UQ 63V0 GRM188R71E473 KA01D B32921C3333M B32921C3103M GRM39COG470J 50 B32922C3104M GRM1555C1H102 JA01D C3225X7S1H106 M GRM31CR71E106 KA12 GRM155R71H221 KA01D GRM1885C1H102 JA01 750 311 895 750312496 ANY ANY ANY VISHAY/DALE ANY ANY VISHAY/DALE ANY CRCW2512820RJ NEG CRCW0805750KJ NEA ANY VISHAY/DALE VISHAY/DALE CRCW060310K0F KEA CRCW06032M10 FKEA Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G R17 R18 R19 R20 R21 R22 R25 R26 U1 BR1 D1 D2, D3 D4 D5 ZD1 ZD2 ZD3 Q1 Q2 Q3 Q4 Q5 Q6, Q7 Table 3 Test report RES 22Ω 1/10W 5% 0603 SMD RES 3.92KΩ, 1/10W 1% 0603 SMD RES 240KΩ 1/8W 1% 0805 SMD RES 604KΩ 1/10W 1% 0603 SMD RES 100KΩ 5% 0402 SMD RES 3.6KΩ 1W 5% 2512 SMD RES 0.91Ω 1/8W 1% 0805 SMD RES 6.81Ω 1% 0805 SMD ICL8002G, P-DSO-8 RECT BRIDGE GPP 400V 0.8A MBS-1, 4-SOIC DIODE GP 200V 250mA MINIMELF DIODE SWITCH SW 75V .5A MINIMELF DIODE SUPER FAST 1A 600V SMA DIODE SCHOTTKY 100V 10A, SMPC DIODE ZENER 18V 150mW SOD-323 DIODE ZENER 12V 350mW SOT23-3 DIODE ZENER 6.8V 150mW SOD-323 TRANS PNP BIPOLAR 65V SOT23-BEC TRANS PNP BIPOLAR 300V SOT23-3 MOSFET N type, 600V , 190mΩ 600mΩ 600VOLT MOSFET, DPAK 45Ω 600VOLT MOSFET, SOT89 TRANS NPN BIPOLAR 65V SOT323 ANY VISHAY/DALE CRCW06033K92F KEA ANY ANY ANY VISHAY/DALE ANY ANY Infineon Comchip Technology Micro Commercial Co Micro Commercial Co MICRO COMMERCIAL VISHAY CRCW25123K60J NEG ICL8002G B4S-G BAV102-TP DL4151-TP ES1J-LTP V10P10 Diodes Inc DDZ9705S Diodes Inc BZX84C12-7-F Diodes Inc DDZ9692S-7 Diodes Inc BC856B-7-F Diodes Inc MMBTA92-7-F INFINEON INFINEON IPI60R190C6 IPD60R600C6 INFINEON BSS225 Diodes Inc. BC846BW-7-F Bill of Materials 19 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G 10 Transformer Figure 19: Test report Transformer 20 Revision 1.0 June, 2012 PAR38 EVAL-LED-ICL8002G The PCB layout is designed for Class 2 insulation. However, this transformer used on this evaluation board is not designed for Class 2 isolation. If class2 insulation is required please contact a custom magnetic supplier for assistance in this design or use our design tool at www.Infineon.com/lightdesk. Many options are available for core and bobbins to provide Class 2 isolation. For example, the pin-out of the PQ20/16 is very similar to the RM8 and provides better form factor with more creepage for class2 insulation than the RM8 bobbin. 11 Related Documentation at Infineon ICL8002G Datasheet: http://www.infineon.com/cms/en/product/channel.html?channel=db3a3043266237920126b 71e3a221e91 Design Guidelines ICL8001G/ ICLS8082: http://www.infineon.com/dgdl?folderId=db3a304314dca389011561889ef01fe7&fileId=db3a 30432a7fedfc012a8e9ff4d40493 Infineon Light Desk Design Tool: www.Infineon.com/Lightdesk Infineon CoolMOS™ High oltage mosfets: www.infineon.com/coolmos Infineon OptiMOS™ Mid / low voltage Mosfets: www.infineon.com/optimos Demo board Order code: SP000993130 www.i nfineon. com Published by Infineon Technologies AG PAR38