A p p l i c a t i on N o t e , V 1 . 2, O c t . 20 0 3 TDA 4 863 AN-PFC-TDA 4863-3 Calculation-Tool for PFC-Preconverter using TDA 4863 Author: Wolfgang Frank http://www.infineon.com/pfc Power Management & Supply N e v e r s t o p t h i n k i n g . Calculation-Tool for PFC-Preconverter using TDA 4863 Revision History: 29.10.2003 Previous Version: 1.1 Page Subjects (major changes since last revision) 2 update V1.2 For questions on technology, delivery and prices please contact the Infineon Technologies Offices in Germany or the Infineon Technologies Companies and Representatives worldwide: see our webpage at http://www.infineon.com. Edition 29.10.2003 Published by Infineon Technologies AG, St.-Martin-Strasse 53, 81669 München, Germany © Infineon Technologies AG 2002. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as warranted characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Infineon Technologies is an approved CECC manufacturer. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide. 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. Calculation-Tool for PFC-Preconverter using TDA 4863 Table of Contents Page 1 Short Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Related PFC Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 3.1 3.2 3.3 3.4 Calculation Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Output Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multiplier Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inductor Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Summary of Used Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Application Note 3 5 5 5 6 6 V1.2, 29.10.2003 Calculation-Tool for PFC-Preconverter using TDA 4863 Short Description 1 Short Description This application note describes the handling of the calculation tool “PFCCal-DCM_1.xls” which is available on our website http://www.infineon.com/pfc. It is an excel-sheet and allows a flexible use for PFC preconverters used in many switch mode power supplies. The calculation is based on the condition, that the switching frequency is always above a generic minimum frequency. Please note, that the calculation tool is only suitable for DCM-designs using TDA 4863. There is no warranty for the results when using other IC. The first sheet is a README-sheet and give a rough overview of the calculation flow. The second sheet is the calculation itself followed by two sheets providing the databases for the ferrite cores and resistive components. For further information, please refer to the Infineon application notes concerning TDA 4863 and PFC ([1], [2], [3]). 2 Related PFC Circuit Figure 1 shows the schematic of the PFC preconverter which the tool is related to. All components are identically enumerated as in PFCCalc.xls. L1 D5 VOUT DC R8 D6 R12 D1...D4 L2 VOLTAGE AMPLIFIER OUTPUT C1 2,5V Reference Undervoltage Lockout 12,5V - 10V Internal Supply 2 Restart Timer 2,2V C6 VIN AC R2 C2 VOLTAGE SENSE 1 0,2 V 0,2V C4 0 & 0 & 0 0 40µA 0 0 8 S Q R Q 5k 3 R7 M1 0V...4V Multiplier Q1 7 DRIVE OUTPUT 0 6 200ns LEB C1 10k M3 QM = M1*(M2-VFB)*K 0,3 V-1< K < 0,7V-1 VFB = 2,5V C4 VCC R10 0 0,6V M2 2,5V...4,3V MULTIPLIER & 0 0 R6 C8 5V 16V 0 R4 5 1,5V 1,0V TDA 4863 C5 VOP 1,2V C2 C3 R9 ZERO CURRENT DETECTOR GROUND C10 4 CURRENT SENSE 1,0V R11 R5 GND Figure 1 Schematic of PFC Circuit Application Note 4 V1.2, 29.10.2003 Calculation-Tool for PFC-Preconverter using TDA 4863 Calculation Sections 3 Calculation Sections The color of the excel cells indicate their function. Yellow cells represent input cells. They ask for basic data being filled in by the user. Nevertheless, they may also contain values by default. Green cells indicate that the value shown is the result of a component according to Figure 1. White cells are protected against any inputs. Pull-down menus give the user a choice of possible values for the related component. The choice of the menu entry is not mandatory. It is still possible to use individual values which are directly typed into the cells. 3.1 Input Section The input values of this section are: • • • • • RMS-value of lowest AC input voltage Vinmin RMS-value of lowest AC input voltage Vinmax Rated output power of preconverter Pout Estimated efficiency eta Minimum switching frequency fp These values define the maximum inductor current IinpmaxHF which results in the shunt resistor R11 according to Figure 1. 3.2 Output Section This section calculates the voltage divider consisting of R4 and R5 according to Figure 1. It is used for sensing the output voltage and for the adjustment of the overvoltage protection (OVP) level. In line 24 the necessary resistor value for R5 is calculated based on the projected output voltage and overvoltage level. The next step is to look after the nearest value in the pulldown menu right below in line 27. This will lead to a default value for R4 calculated in line 28. Due to the high voltage stress of resistor R4, it is split into two resistors in series. It is therefore necessary to choose half the value of line 28 in the pull-down menu of line 29. The resulting series resistor and the resulting output voltage as well as the OVP level are displayed in line 30 to 32. Both the value in line 27 and in line 29 can also be manipulated manually by directly filling in the values into the corresponding cell. The tolerance of R4 and R5 are directly influencing the precision of the output voltage and the OVP level. The menus of line 27 and line 29 contain therefore values of the E96 series with a tolerance of 1%. This section calculates also the minimum bus capacitor C8 which provides the specified output characteristics if the mains interrupt for a given holdup time. Application Note 5 V1.2, 29.10.2003 Calculation-Tool for PFC-Preconverter using TDA 4863 Calculation Sections 3.3 Multiplier Section The multiplier section provides the information of the input voltage waveform which has to be traced. This means, that the input voltage is divided with the resistors R6 and R7 according to Figure 1 and fed into the multiplier pin. Again, R6 is split into two resistors in series, because it is also stressed by higher voltage. Therefore, the value chosen in the menu of line 40 is doubled in line 41 and is highly recommended to be high-ohmic in order to avoid unnecessary losses. Then choose the nearest value of resistor R7 in the menu in line 43. The values of R6 and R7 must be changed if the test results in “NO” in line 44. The tolerance of these components needs not to be very low, because it has almost no influence on the THD or the power factor. The entries of the menus are taken from the E12 series with 5% tolerance. 3.4 Inductor Section The input values of this section are: • the maximum flux density swing during one pulse period • the saturation flux density • the core type The lines 55, 57 and 58 show default values, when using a core type of the pull-down menu. They are taken from the EPCOS data book [4]. However, it is also possible to fill in individual values there. The lines 52 to 58 result in the airgap of the core which is given in line 59. If a core of the menu of line 54 is used, then the menu of line 60 will show all available airgaps of this type. Again, one can neglect those values and fill in an individual one. Then the next integer number has to be inserted in line 63 and the effective inductance of the PFC inductor is shown in line 64. The test in line 65 and 66 proves, if the core probably saturates. It is recommended to change to a larger airgap or to a larger core if the saturation current is smaller than the highest peak inductor current IinpmaxHF. The design of the detector winding which is necessary to capture the zero crossing of the inductor current is dependent on the IC supply circuit used. Please refer to [1] for further information. Application Note 6 V1.2, 29.10.2003 Calculation-Tool for PFC-Preconverter using TDA 4863 Summary of Used Nomenclature 4 Summary of Used Nomenclature Physics: General identifiers: Special identifiers: A .........cross area b, B .....magnetic inductance C .........capacitance d, D .....duty cycle f...........frequency i, I ........current L..........inductance N .........number of turns p, P .....power t, T.......time, time-intervals v, V......voltage W ........energy η..........efficiency AL ........... inductance factor V(BR)CES .. collector-emitter breakdown voltage of IGBT VF........... forward voltage of diodes Vrrm .......... maximum reverse voltage of diodes big letters: contant values and time intervals small letters: time variant values K1, K2 ..ferrite core constants Components: C .........capacitor D .........diode IC ........integrated circuit L..........inductor R .........resistor TR .......transformer Indices: AC.......alternating current value DC.......direct current value BE .......basis-emitter value CS.......current sense value OPTO..optocoupler value P .........primary side value Pk........peak value R .......... reflected from secondary to primary side S .........secondary side value Sh .......shunt value UVLO ..undervoltage lockout value Z..........zener value Application Note 7 fmin......... value at minimum pulse frequency i ..............running variable in ............input value max ........maximum value min .........minimum value off ...........turn-off value on ...........turn-on value out ..........output value p .............pulsed rip ...........ripple value 1, 2, 3 .....on-going designator V1.2, 29.10.2003 Calculation-Tool for PFC-Preconverter using TDA 4863 References 5 References [1] Infineon Technologies AG: TDA 4863 - Power factor and boost converter controller for high power factor and low THD; Preliminary data sheet; Infineon Technologies AG; Munich; Germany; 07/01. [2] M. Herfurth, W Frank: TDA 4863 - Technical description; Application Note AN-PFC-TDA4863-1; Infineon Technologies; Munich; Germany; 02/02. [3] W Frank: TDA 4863 - Getting started with TDA 4863; Application Note AN-PFC-TDA4863-2; Infineon Technologies; Munich; Germany; 02/02. [4] EPCOS: Data book library 2002; data book CDROM; EPCOS; Germany; 2001. Application Note 8 V1.2, 29.10.2003 In f i n e o n g o e s f or B u s i n e s s E x c el len c e “Business excellence means intelligent approaches and clearly defined processes, which are both constantly under review and ultimately lead to good operating results. Better operating results and business excellence mean less idleness and wastefulness for all of us, more professional success, more accurate information, a better overview and, thereby, less frustration and more satisfaction.” Dr. Ulrich Schumacher www.infineon.com Published by Infineon Technologies AG