Version 1.1, March 2008 Application Note CoolSET™ & CoolMOS™ Ultra Wide Input Range, HV-BIAS Supply for SMPS with ICE2B265 and SPA02N80 Author: Bernd Ilchmann Finepower GmbH 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 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Contents: 1 Short Description..................................................................................................................... 3 2 Features .................................................................................................................................. 3 3 General Description ................................................................................................................ 4 4 Description of Function and Components .............................................................................. 5 5 Results..................................................................................................................................... 7 5.1 Output Voltage ..............................................................................................................7 5.2 Cross Regulation ...........................................................................................................7 5.3 Protection Features.................................................................................................... ........8 5.4 Efficiency ......................................................................................................................9 6 Construction .......................................................................................................................... 10 7 Bill of Materials ...................................................................................................................... 11 8 References ............................................................................................................................ 13 WARNING ! This bias power supply board works with mortally high voltage! Furthermore, parts of the circuitry are not insulated from the line input. The user has to make sure that no danger or risk can occur for himself or for any other person while voltage is applied to this board. Dependant on the final application this converter must be protected by a fuse or any other element which can disconnect the applied maximum voltage of 800V DC in case of failure. Page 2 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 1 Short Description This application note describes a universal ultra wide input voltage range power supply module. It is typically used as housekeeping power supply in professional SMPS. Typically driven from the bulk capacitor after any PFC stage or from the bulk after a three phase rectifier any DC input voltage from 120V DC to 800V DC may be applied to this board. It provides a primary (line connected) output voltage as well as a secondary (line isolated) output voltage of 15V DC (both). The sum of the output power is up to 12W shared to both outputs. One typical application is shown in figure 1 below. Figure 1: Principle application of the HV-Bias circuit 2 Features The 12W HV -BIAS demonstration board shows a complete two-output DC to DC Flyback circuit. To achieve an ultra wide input voltage range up to 800VDC a transistor with 1200V to 1500V breakdown capability is necessary. This makes the design expensive and reduces the efficiency by its parasitics. On this HV-Bias module Infineon’s 600V CoolSET™ is used together with a further 600V or 800V CoolMOS™ transistor. The user of this module is able to supply any primary or secondary connected circuitry (µC’s, PWM’s, drivers, relays etc.) independent from the state (short circuit, no load, stand-by or remote-off) of the main SMPS system. Page 3 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 By connecting the input terminals of the CoolBIAS Module across a line filter, rectifier and a sufficient bulk capacitor to the AC line a universal ultra wide input range AC power supply is realizable. A very high reliability of this module due to the CoolSET’s protection features and robustness of the integrated and external CoolMOS transistor is achieved. Technical specification: 1) Input Voltage Range: 120 VDC ... 800V DC Total Output Power: 12W Output Power Limit: ca. 15W Output 1 Voltage, primary: 15V DC ± 8% Output 2 Voltage, secondary: 15V DC ± 12% Short Circuit protection: yes, with auto restart Efficiency (typ.) @ rated load: 73 ...83 % Switching Frequency: 67kHz PWM & Power Device: ICE2B265 & SPA02N80 2) 2) 3) 4) 1) Start-up behavior – see text 2) Output 1 & 2 Load Sharing: from 80% / 20% up to 20% / 80% 3) Depending on input voltage 4) SPA02N80 may be replaced by a (cheaper) 600V CoolMOS if input voltage overshoot is limited to 800V. 3 General Description The input of the HV-Bias module can be connected to any bulk (after rectification) from 115V AC single phase up to 400V AC multi phase AC front end as well as to the bulk after any PFC stage. Due to the very high maximum input voltage of 800V DC and the reflected output voltage of approx. 200V the breakdown capability of the internal switch in the ICE2B265 is exceeded as well as in its high voltage version (ICE2A280). A series connection of a cheap 600V or 800V CoolMOS™ transistor with the internal CoolSET™ MOSFET forms a self driven cascode witch is able to handle a maximum drain voltage above 1kV. The circuit around the CoolSET™ is very similar to the standard application and not described in this paper therefore. Page 4 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Fig. 2: Principle Application of the CoolBIAS Power Supply Figure 2 shows the complete schematic of the HV-Bias module. Beside the standard CoolSET™ periphery only few additional components are required to achieve the high voltage capability of the power switch. 4 Description of Function and Components The function of the self driven cascode essentially depends on the chosen zener diode D4. After applying the high input voltage C3 is charging across R1 to R4. Furthermore, these resistors do share the input voltage across the serial connected input electrolytic capacitors. The gate voltage of Q1 (across R7 to R10) tracks the input voltage until it is clamped by D4 to approx. 550V. Due to the source follower circuitry of Q1 the maximum drain voltage for IC1 is limited around the voltage across D4. Page 5 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 When C3 is charged up to the start voltage of IC1 the internal MOSFET will switch on and forces the source of the external MOSFET Q1 close to GND. The charge in the junction of the high voltage zener is transferred across R11 to the gate of Q1. D6 limits its maximum gate voltage to 15V. By this way both MOSFET’s switch on nearly simultaneously. The transformers primary winding is applied to the input voltage now. When the PWM controller of IC1 switches off - the internal MOSFET disconnects the transformer’s primary winding from the input. So the voltage across the opened CoolSET™ switch rises (driven by the stored inductive energy) until it is clamped by the source follower Q1. Because the source of Q1 was held down by IC1 before, the gate voltage of Q1 was approx. 15V. So the fast rising drain voltage of IC1 switches off Q1 nearly in the same time (when the voltage is higher than approx. 12V). The increasing voltage charges the junction of D4 across D6, R11 until it is clamping. From now the voltage follower Q1 starts working and stops further increasing of the voltage across IC1. So any additional voltage increases across Q1 until its maximum value. VIN = 280V DC VIN = 400V DC VIN = 600V DC VIN = 800V DC Figure 3: From top to bottom: VD-GND (Q1), VD-S (Q1), VD-GND (CoolSET™) Page 6 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 5 Results 5.1 Output Voltage The nominal Output voltage on the primary as well as on the secondary side is 15V DC. By a 2% zener diode and a resistive divider this value is realized in a sufficient accuracy. Due to the primary located regulation loop the primary output voltage is quite exact and no dependant from line and load changes on the secondary side. So no clamping zener diode is required to protect the IC from over voltage. If in any application only one (primary) output voltage is required, the user may connect the secondary output parallel to the primary. Figure 4 shows the primary and secondary output voltage versus VIN . Vo = f(Vin); param. Load 16 15,8 15,6 Vo / Vdc 15,4 15,2 15 UO(P,S) @ full load UO(P,S) @ half load 14,8 14,6 14,4 14,2 14 100 200 300 400 500 600 700 800 Vin / Vdc Figure 4: Line Regulation at half and full load 5.2 Cross Regulation The inductive coupled secondary output voltage follows the regulated voltage with a tolerance caused by the leakage inductance between the primary bias and the secondary winding. Additionally, some tolerances in the rectifier diode (forward voltage or temperature) may cause deviation. However, the secondary unregulated output voltage under balanced load sharing tracks the primary voltage very excellent due to the optimized transformer design. Under cross load condition (20%/80% up to 80%20%) the secondary output voltage stays within the designated tolerances. Figure 5 shows the cross load behavior of the secondary output voltage. Page 7 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Cross Regulation @ Vin = 400V20 Output Voltage 18 16 VO(P) / V 14 VO(S) / V 12 10 8 0% 20% 40% 60% 80% 100% Primary Load Ratio Fig. 5: Cross Regulation while secondary side is shunted with 1k? 5.3 Protection Features Shorted output on the primary side as well as on the secondary side cause the hiccup mode of the controller with no rising of any output voltage. After removing the output short the converter starts automatically. The output power limit, adjusted by the value of the current sense resistor is set to approx. 15W. By exceeding the output power above this limit the converter goes into the hiccup mode with auto restart as well as under short condition. This avoids excessive stress from any device. By removing R5 from the board the primary regulation loop is cut off. Usually, the output voltage of any flyback converter is rising up to the energy limit, destroying the connected circuitry and the converter. In the described HV-BIAS module a self protection against this failure is introduced in the controller circuit. The PWM controller is detecting the loss of the regulation loop and switches to the hiccup mode. Figure 6 demonstrates that the overload shutdown which is relatively constant over the ultra wide input voltage range due to the adaptive overload threshold in the CoolSET™-PWM. Page 8 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Over Load Shutdown vs. Input Voltage 20 Overload Power 15 10 5 0 100 200 300 400 500 600 700 800 Input Voltage Fig. 6: Overload Shutdown versus Input Voltage In the given design there may be some start-up problems with high external output capacitance at rated power when starting at low line (120V DC ). Due to the interaction between soft-start capacitance, current sense resistor and start up current a tuning of these components may be necessary if starting is required at very low line. After the converter is started, it works down to approx. 100V DC without any problems. 5.4 Efficiency The efficiency of the HV-Bias module is not the main criterion for the design due to its low power consumption. Especially in high voltage or in three phase designs the total transferred power is much more than the rated power level of this bias module. Furthermore, the efficiency depends on the increasing switching losses going square with the input voltage. Nevertheless, the overall efficiency of the converter is sufficient high. Figure 7 shows the efficieny of the converter versus input voltage at rated output power and half of the rated output power. Page 9 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Efficiency vs. Input Voltage 100% 90% Effcy. / % 80% PO(tot) = 12W 70% PO(tot) = 6W 60% 50% 40% 100 200 300 400 500 600 700 800 Input Voltage / Vdc Figure 7: Efficiency of the HV-Bias Module versus Input Voltage 6 Construction The converter is designed on a small double sided PCB. So trough hole devices (transformer, IC1, Q1, electrolytic capacitors etc.) can be placed on the opposite side from the SMD’s. Figure 8: shows the PCB layout for the top and bottom side layer. Figure 8: The HV-Bias Module – nearly original size Page 10 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Figure 9: Layout TOP - left and BOTTOM (mirrored) – right Figure 10: Components placement on the top (left) and the bottom (right) side 7 Bill of Materials (part list) Part Value 1 Value 2 Ordering Code Supplier or Manufacturer BR1 Wire bridge 0.6mm C1 10µF / 450V electrolytic cap, grid: 5mm various C2 10µF / 450V electrolytic cap, grid: 5mm various C3 47µF / 50V electrolytic cap, grid: 2,5mm various C4 470µ / 25V- Low ESR electrolytic, grid: 5mm various C5 330p / 1kV NP0, grid. 5.08mm various Page 11 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 C6 0µ1 / 50V X7R, SMD1206 various C7 1µ0 / 25V X7R, SMD1206 various C8 2n2 / 50V NP0, SMD1206 various C9 1000µ / 25V - Low ESR electrolytic, grid: 5mm various D1 ES3D Ultra Fast Diode, SMC Vishay - GS D2 LL4148 Diode SMD various D3 ZMM12 Zener diode 12V, SMD various D4 P4KE550 HV-Zener, 550V Vishay - GS D5 US1M Ultra Fast Diode , SMA Vishay - GS D6 ZMM15 Zener diode 15V, SMD various D7 ES3D Ultra Fast Diode, SMC Vishay - GS IC1 ICE2B265 CoolSET™ PWM + Mosfet Infineon Q1 SPA02N60-C3 CoolMOS™ 600V / 2A Infineon Q2 MMBT2222 NPN transistor, SOT23 ON Semiconductor R1 330k / 0,2W SMD1206 various R2 330k / 0,2W SMD1206 various R3 330k / 0,2W SMD1206 various R4 330k / 0,2W SMD1206 various R5 3k6 / 0,2W SMD1206 various R6 4k7 / 0,2W SMD1206 various R7 1M0 / 0,2W SMD1206 various R8 1M0 / 0,2W SMD1206 various R9 1M0 / 0,2W SMD1206 various R10 1M0 / 0,2W SMD1206 various R11 10R / 0,2W SMD1206 various R12 22R / 0,2W SMD1206 various R13 120k / 1W Metal film, grid 10,16 various R14 1R8 / 0,2W SMD1206 various TF1 UEI18.0 Flyback Transformer Fa. Lasslop Page 12 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 8 References [1] Infineon Technologies AG: “CoolSET™- F2 Offline SMPS Current Mode Controller with integrated 650V/800V CoolMOS ” Datasheet; Munich; Germany; 08/2002 http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179 [2] Infineon Technologies AG: “SPP02N80C3” 800V CoolMOS™ Transistor; Datasheet; Munich; Germany; 07/2003 http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=25591&cat_oid=-8176 [3] Infineon Technologies AG: (H. Zöllinger, R. Kling) “AN-SMPS-ICE2xXXX-1 – Application Note: CoolSET ICE2xXXX for OFF-Line Switch Mode Power Supply (SMPS) Munich; Germany; 02/2002 http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179 [4] Infineon Technologies AG: (B. Ilchmann) “6W Bias Supply for SMPS with ICE2A0565Z”; Application Note: AN-EvalMF2-ICE2A0565Z-1; Munich; Germany; 09/02 http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179 Page 13 of 14 Ultra Wide Input Range, HV-Bias Supply for SMPS with ICE1B265 & SPA02N80 Revision History Application Note AN-EvalMF2-ICE2A0565Z-1 Actual Release: V1.1 Date:11.03.2008 Page of Page of actual prev. Rel. Previous Release: V1.0 Subjects changed since last release Rel. 2 of 14 ---------- „WARNING“ (Safety Issue regarding fuse protection) 5 of 14 Schematic (Fig. 2) modified 10 of 14 Photo (Fig. 8) updated 11 of 14 Fig. 10: Placement for top side modified 11 of 14 Bill of Material modified (ex F1, add BR1) 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 CoolMOS and CoolSET are trademarks of Infineon Technologies AG. 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] Edition 2008-03-11 Published by Infineon Technologies AG, Am Campeon 1-12 D-81726 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 y our 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 expect ed 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. Page 14 of 14