EPR-000013 CISPR22B/EN55022B VAC-115 CISPR22B EN55022B IEC950 UL1950

Engineering Prototype Report (EP13) 43 W / 57 W pk, 5 Output TOPSwitch-GX (TOP246Y) Power Supply Specification 185 - 265 VAC

Title Engineering Prototype Report (EP13) 43 W / 57 W pk, 5 Output TOPSwitch-GX (TOP246Y) Power Supply Specification 185 - 265 VAC input, 3.3 V / 3 A, 5 V / 3.2 A, 12 V / 0.6 A (1.8 A pk), 18 V / 0.5 A, 30 V / 0.03 A output. (Details for 115 VAC conversion included) Target Applications Set top box with internal hard drive, or other multiple output applications Author Power Integrations Applications Department Document Number EPR-000013 EPR-000013 Date 08-May-2001 Revision 1.0 Features · · · · · · · · · · · · Compact Design (6.875" L X 2.56" W X 1.56" H) 43 W steady state output power at 50 °C ambient, free convection High efficiency (75% minimum at 180 VAC input, maximum continuous load) Low no-load power consumption (< 0.7 W @ 180 VAC, < 0.8 W @ 265 VAC) Multiple section transformer for low cost automated production Excellent output voltage tracking and cross regulation Primary soft-start minimizes component stress during start-up Low conducted EMI due to frequency jittering: meets CISPR22B/EN55022B CISPR22B/EN55022B Line overvoltage shutdown provides extended line surge protection Hysteretic thermal shutdown allows automatic supply recovery after fault removal Low component count with single sided printed circuit board Surge immunity up to 4 kV (surge or 100 kHz ring wave) Power Integrations, Inc. 5245 Hellyer Avenue, San Jose, CA 95138 USA. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 08-May-2001 Table Of Contents 1 2 3 4 5 6 7 Introduction .4 Power Supply Specification .5 Schematic .6 Circuit Description.7 PCB Layout.10 Bill Of Materials.11 Transformer Specification .13 7.1 Electrical Specifications.13 7.2 Materials.13 7.3 Winding Instructions .14 7.4 Transformer Sources.14 8 Transformer Spreadsheets .15 8.1 230 VAC, 60 W Peak Load .15 8.2 230 VAC, 45 W Steady State Load.18 9 Performance Data.21 9.1 Efficiency.21 9.2 No-load Input Power.21 9.3 Regulation .22 9.3.1 Maximum load all outputs .22 9.3.2 Peak load all outputs.22 9.3.3 3.3 V Min. load, 12 V peak, other outputs fully loaded .23 9.3.4 12 V Min. load, other outputs at maximum load condition.23 9.3.5 12 V Peak load, 30 V min. load, other outputs at max. load.24 9.3.6 5 V and 3.3 V min load, all other outputs maximum .24 10 Thermal Performance .25 11 Waveforms.26 11.1 Drain Voltage and Current, Normal Operation.26 11.2 Output Voltage Start-up Profile.26 11.3 Drain Voltage and Current Start-up Profile .27 11.4 Load Transient Response (75% to 100% Load Step).28 11.5 Output Ripple Measurements .29 11.5.1 Ripple Measurement Technique .29 11.5.2 Measurement Results at 180 VAC.30 11.5.3 Measurement Results at 230 VAC.31 12 Control Loop Measurements.32 12.1 180 VAC Maximum Load .32 12.2 230 VAC Maximum Load .33 12.3 265 VAC Maximum Load .34 13 Conducted EMI .35 14 AC Surge and 100 kHz Ring Wave Immunity .35 14.1 Common Mode Surge, 1.2/50 µsec .36 14.2 Differential Mode Surge, 1.2/50 µsec .36 14.3 Common Mode, 100 kHz Ring Wave.37 14.4 Differential Mode, 100 kHz Ring Wave .37 Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 2 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 15 Appendix A EP13, 115 VAC Version . 38 15.1 115 VAC Option Power Supply Specification. 38 15.2 Schematic for EP13 115 VAC-only Version. 39 15.3 EP13 115 VAC Version Circuit Description . 40 15.4 EP13 115 VAC Transformer Drawing . 41 15.5 Electrical Specifications . 41 15.6 Materials . 42 15.7 Transformer Construction Diagram. 42 15.8 Winding Instructions. 43 15.8.1 Shield Foil Assembly . 44 Secondary Foil Assembly. 44 15.8.3 Design Notes. 44 15.9 EP13 115 VAC Transformer Spreadsheets . 45 15.9.1 115 VAC, 60 W Peak Load . 45 15.9.2 115 VAC, 45 W Steady State Load. 48 15.10 List of Included Parts for 230 VAC-115 VAC-115 VAC Conversion . 51 15.11 EP13 230 VAC-115 VAC-115 VAC Conversion Instructions . 51 15.11.1 Required Tools and Supplies. 51 15.11.2 Conversion Instructions . 51 16 Appendix B Miscellaneous Custom Parts . 52 16.1 Secondary Heat Sink . 52 17 Revision History . 53 Page 3 of 56 Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 08-May-2001 1 Introduction This document is an engineering report describing a 230 VAC input, 5-output flyback supply utilizing TOPSwitch®-GX (TOP246Y). The supply is rated for 43 W continuous output power, with 57 W of peak power capability for starting a disk drive. The design is optimized for high-end set-top box applications, but is easily adapted for other multiple output uses such as VCRs, DVD players, cable modems, and direct satellite receivers. The design kit includes a component kit and instructions for converting the supply to 115 VAC input operation. This document contains the power supply specification, schematic, and bill of materials, transformer documentation, printed circuit layout, and performance data. 1.56" 6.875" 2.56" Figure 1 - EP13 Populated Circuit Board. Figure 2 - EP13 230 VAC Input to 115 VAC Input Retrofit Kit. Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 4 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 2 Power Supply Specification Description Input Voltage Frequency No-load Input Power (230 VAC) Output Output Voltage 1 Output Ripple Voltage 1 Output Current 1 Output Voltage 2 Output Ripple Voltage 2 Output Current 2 Output Voltage 3 Output Ripple Voltage 3 Output Current 3 Output Voltage 4 Output Ripple Voltage 4 Output Current 4 Output Voltage 5 Output Ripple Voltage 5 Output Current 5 Total Output Power Continuous Output Power Peak Output Power Efficiency Symbol Min Typ Max Units Comment VIN fLINE 180 47 230 50/60 265 64 0.75 VAC Hz W 2 Wire no P.E. VOUT1 VRIPPLE1 IOUT1 VOUT2 VRIPPLE2 IOUT2 VOUT3 VRIPPLE3 3.14 3.30 3.00 5.00 V mV A V mV A V mV ± 5% 20 MHz Bandwidth 1.0 4.75 3.46 33 3.00 5.25 50 3.20 12.84 120 1.00 11.16 3.20 12.0 * 0.30 0.60 1.8 A VOUT4 VRIPPLE4 IOUT4 VOUT5 VRIPPLE5 IOUT5 16.74 18.00 19.26 180 0.5 36.3 200 0.03 V mV A V mV A 43 57 W W % POUT POUT_PEAK 0.01 33 - 75 ±7% 20 MHz Bandwidth * IOUT3 0.5 29.7 ±5% 20 MHz Bandwidth Peak, 10 s max, thermally limited ±7% 20 MHz Bandwidth ±10% 20 MHz Bandwidth Measured at POUT (43 W), 25 oC Environmental Conducted EMI Meets CISPR22B CISPR22B / EN55022B EN55022B Safety Designed to meet IEC950 IEC950, UL1950 UL1950 Class II 1.2/50 µs surge, IEC 1000-4-5, 12 series impedance, differential and common mode 100 kHz ring wave, 500 A short circuit current, differential and common mode Surge 4 kV Surge 4 kV Ambient Temperature Page 5 of 56 TAMB 0 50 o C Free convection, Sea level Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 08-May-2001 3 Schematic Figure 3 - EP13 Schematic. Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 6 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 4 Circuit Description The EP13 is a five-output flyback power supply using the TOP246Y integrated circuit. The circuit shown in Figure 3 provides 43 W continuous power, with peak capability of 57 W (thermally limited). Input voltage range is 180-265 VAC. AC input power is rectified and filtered by D1-4 and C2 to provide a high voltage DC bus, which is applied to the primary of transformer T1. The TOP246Y DRAIN pin drives the other side of the transformer primary. Components D5, VR1, R2 and C5 clamp the DRAIN voltage leakage inductance spike to below the 700 V maximum rating of the TOPSwitch. The TOPSwitch-GX family provides several new features, as well as extended specifications. The EP13 power supply is designed to take advantage of several of these features. Resistor R1 connected to the LINE SENSE pin (L) of TOPSwitch-GX U1 is used to implement the built-in line voltage feed forward and overvoltage protection features. The line feed forward feature modulates the control circuit of the TOPSwitch-GX with the AC line frequency ripple component of the input DC, reducing the line frequency ripple at the output of the supply. This simplifies the design of the power supply control loop by reducing the amount of control loop gain required at the line ripple frequency in order to meet output ripple specifications. The overvoltage feature shuts down the power supply if the rectified DC bus voltage exceeds approximately 450 V, set by the value of R1. The supply resumes operation when the bus voltage falls again below the overvoltage threshold value. This feature allows the supply to withstand severe line transients or extended surge conditions without damage. This is an attractive feature for products designed for markets with poor power quality. Resistor R4 connects to the EXTERNAL CURRENT LIMIT pin (X) of U1 and is used to externally program the device current limit to just above the peak primary current of the supply at maximum peak load, minimum line voltage. This allows the transformer to be better optimized for the chosen operating conditions, while at the same time avoiding transformer core saturation during start-up or overload conditions. Transformer optimization choices can include using a smaller core (less expensive transformer), fewer primary turns (less leakage inductance), or higher primary inductance (more continuous operation, less TOPSwitch dissipation). The EP13 transformer design does not take full advantage of the flexibility offered by the TOPSwitch-GX due to secondary volts per turn required to minimize voltage error between 3.3 V and 5 V outputs. The secondary turns were deliberately chosen to optimize output voltage centering with the fewest possible number of turns. The reflected Page 7 of 56 Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 08-May-2001 voltage at the primary was fixed at 100 V to optimize output cross regulation, thus fixing the number of primary turns. A design with fewer output voltages can take better advantage of the design flexibility offered by the TOPSwitch-GX family. D6 and C3 provide a DC voltage of approximately 12 V to power the TOP246Y. A relatively large value of C3 (1 µF) is used to provide bias voltage ride-through during severe output load transients. Capacitor C4 filters the internal bias supply of the TOPSwitch-GX, providing the necessary peak currents to drive the gate of its internal high-voltage MOSFET. Capacitor C4 also determines the TOPSwitch-GX auto-restart frequency, and along with resistor R3, helps to compensate the power supply control loop. Transformer T1 utilizes a nine section slotted bobbin designed for an automated production environment. Primary and secondary windings are applied in alternate bobbin slots using ordinary magnet wire. The slots provide the necessary safety isolation and creepage distance between the primary and secondary windings without the need for additional insulation of any kind. The large number of winding slots provides sufficient interleaving of primary and secondary windings to reduce the leakage inductance to a tolerable value, while the open construction of the transformer reduces winding temperature rise, allowing use of relatively fine wire, further facilitating automatic winding. Diodes D7, 8, 9, 10 and 11, along with capacitors C7, 9, 11, 13, 14, 16 and 17 are used to rectify and filter the five output secondary windings of T1. Two techniques are used to properly center the output voltages of the supply and to improve cross regulation between outputs. An ultrafast rectifier is used for D10 (5 V output rectifier) instead of a Schottky rectifier. The extra voltage drop of the ultrafast rectifier centers the 5 V output at precisely 5 V. Also, the 12 V, 18 V and 30 V secondary windings are stacked on the cathode side of the 5 V output rectifier (DC stacking) rather than the anode side (AC stacking). This means that the current for these outputs passes through the 5 V output rectifier (D10) as well as their respective output rectifiers (D7, 8, and 9). This increases the dissipation in D10, but has two beneficial effects. First, the extra voltage drop imposed by D10 precisely centers the 12 V output. Also, since the current for the 12 V, 18 V and 30 V outputs passes through D10 and its connecting printed circuit traces, variations in the current from these outputs will modulate the voltage drop across D10 to a certain extent. This change is passed on to the 5 V output, causing the output control loop to change the duty cycle to compensate. This indirect feedback improves the cross regulation of these outputs. Inductors L2, 3, 4, 5 and 6 are used along with capacitors C8, 10, 12, 15 and 18 to provide high frequency filtering for the five outputs of the supply. These filters greatly reduce the switching frequency ripple and high frequency spike noise at the outputs of the supply. Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 8 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply A voltage divider consisting of resistors R10, 11 and 13 monitors the voltage on the 5 V and 3.3 V outputs. The resistor values are weighted so that the voltage feedback loop is controlled mostly by the 5 V output, with some contribution from the 3.3 V output. Sharing the voltage regulation control between the two outputs in this manner improves the cross regulation for the 3.3 V output at the expense of a slight change in the regulation of the 5 V output. The voltage from R10, 11 and 13 is applied to the reference pin of shunt regulator U3. These resistor values and the reference voltage of U3 are used to set the output voltages of the supply. Resistor R7 is used to set the overall gain of the supply control loop, while R8 provides bias current for U3. R9 and C19 provide frequency compensation for U3 to help stabilize the power supply control loop. Capacitor C20 is used to provide open loop feedback through optocoupler U2 during start-up, which in conjunction with the built-in soft start-up feature of TOPSwitch-GX, completely controls the start-up drain current profile, preventing transformer saturation and output overshoot. Optocoupler U2 applies the feedback signal from U3 to the CONTROL pin of U1. Resistor R15 and capacitor C24 form a snubber across D10 that reduces the reverse recovery transient from this diode, improving EMI performance. Inductor L7 is a ferrite bead placed in series with the 12 V, 18 V and 30 V output windings of T1. This bead acts as a small saturable reactor to improve the centering and cross regulation of these outputs. R6 provides a small amount of pre-filtering for the 30 V output, and is used to help prevent peak charging of this output due to leakage spikes. C1, L1 and C6 provide common-mode and differential mode EMI filtering for the power supply. Fuse F1 protects against gross circuit faults. Varistor RV1 is used to clamp differential mode line transients. Thermistor RT1 reduces the initial current surge when AC power is first applied to the circuit. Page 9 of 56 Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 08-May-2001 5 PCB Layout Figure 4 - EP13 Printed Circuit Layout. (Approximately 1:1 Scale) Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 10 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 6 Bill Of Materials EP13 Set Top Supply, 230 VAC Slot Wound XFMR 1/25/01 Bill Of Materials Item Qty Reference Description P/N Manufacturer 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 1 1 1 1 1 1 1 1 2 1 4 2 2 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10, 12 C11 C13, 14,16,17 C15, 18 C19, 23 0.22 µF 250 V, X2 68 µF, 400 V 1 µF, 50 V NHG 47 µF 16 V NHG 1 nF, 1 kV 2.2 µF, Y1 47 µF, 50 V NHG 10 µF, 50 V NHG 330 µF, 25 V HFQ 100 µF, 25 V NHG 390 µF, 35 V HFQ 1000 µF, 25 V HFQ 220 µF,16 V NHG 0.1 µF, 50 V 306 20224 ECO-S2GP680AA ECO-S2GP680AA ECA-1HHG010 ECA-1HHG010 ECA-1CHG470 ECA-1CHG470 ECK-D3A102KBN ECK-D3A102KBN 440LD22 440LD22 ECA-1HHGG470 ECA-1HHGG470 ECA-1HHG100 ECA-1HHG100 ECA-1EFQ331 ECA-1EFQ331 ECA-1EHG101 ECA-1EHG101 ECA-1VFQ391 ECA-1VFQ391 ECA-1EFQ102 ECA-1EFQ102 ECA-1CHG221 ECA-1CHG221 K104M15Z5UF5TH5 K104M15Z5UF5TH5 15 16 1 1 C20 C24 22 µF, 50 V NHG 1 nF, 50 V ECA-1HHG220 ECA-1HHG220 K102K15X7Rf5TL2 Philips Panasonic Panasonic Panasonic Panasonic Cera-Mite Panasonic Panasonic Panasonic Panasonic Panasonic Panasonic Panasonic Beyerschlag /Centralab Panasonic Beyerschlag /Centralab 17 18 4 1 D1-4 D5 1 A, 1000 V 1 A, 600 V, 200 nsec 1N4007 1N4007 1N4937 1N4937 19 20 1 1 D6 D7 Diode, 75 V 1 A, 200 V, 50 nsec 1N4148 1N4148 UF4003 UF4003 21 2 D8, 9 3 A, 200 V, 50 nsec UF5402 UF5402 22 23 1 1 D10 D11 20 A, 200 V, 35 nsec 10 A, 45 V Schottky BYV32-200 BYV32-200 MBR1045 MBR1045 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 1 1 4 1 1 1 1 1 1 2 1 1 1 1 1 1 1 F1 L1 L2-5 L6 L7 R1 R2 R3 R4 R6, 15 R7 R8 R9 R10 R11 R13 R14 Fuse, 250 VAC 3.15 A 20 mH, 0.8 A 3.3 uH, 33 uH, 190 mA Ferrite Bead 2 M, 1/2 W, 5% 68 k, 2 W, 5% Metal Oxide 6.8 , 1/4 W, 5% 9.09 k, 1 %, RN55 10 , 1/4 W, 5% 150 , 1/4 W, 5% 1 k, 1/4 W, 5% 3.3 k, 1/4 W, 5% 9.53 k, 1%, RN55 10 k, 1%, RN55 15 k, 1%, RN55 2.7 k, 1/2 W, 5% 372-1315 ELF-18N008A ELF-18N008A 622-LY-3R3M 622-LY-3R3M 78F330J 78F330J 2643022401 Page 11 of 56 General Semiconductor General Semiconductor General Semiconductor Philips General Semiconductor Wickman Panasonic Toko J.W. Miller Fair-Rite Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 41 42 43 44 45 46 1 1 1 1 1 1 T1 U1 U2 U3 RV1 VR1 XFMR, Custom Slotted Bobbin TOP246Y Optocoupler, graded CTR Shunt Regulator, 1% Varistor, 275 VAC, 14 mm TVS, 200 V, 600 W 47 48 49 50 51 1 1 1 1 1 RT1 J1 J2 HS1 HS2 Thermistor, 10 ohm 1.7 A 3 pin, 0.156 ctr* 14 pin, 0.156 ctr. Heat Sink, TO-220, 1.5" ht. Heat Sink Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com LTV817A LTV817A TL431ACLP TL431ACLP P6KE200 P6KE200 KC012L KC012L 26-60-2030 26-60-2140 531102N02500 531102N02500 08-May-2001 Orega Power Integrations Liteon TI General Semiconductor Keystone Molex Molex Aavid Custom Page 12 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 7 Transformer Specification Figure 5 - EP13 Multiple Slot Transformer. 7.1 Electrical Specifications Electrical Strength Primary Inductance Resonant Frequency Primary Leakage Inductance 7.2 1 minute, 60 Hz, from Pins 1-9 to Pins 10-18 Pins 1-5 with Pins 3-4 shorted together, all other windings open, 130 kHz measurement frequency Pins 1-5 with Pins 3-4 shorted together, all other windings open Pins 1-5 with Pins 3-4 shorted together, Pins 1018 shorted together, 130 kHz measurement frequency 3000 VAC 487 µH +/-10% 2 MHz minimum 15 µH maximum Materials Item [1] [2] [3] Description 2 Orega SMT18 SMT18 Core/Bobbin Set, Gap core for AL of 180 nH/T Magnet Wire, Solderable Double Coated 0.25 mm/30 AWG Epoxy Glue Page 13 of 56 Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 7.3 08-May-2001 Winding Instructions Slot # Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7 Slot 8 Slot 9 Start Pin Start Pin 5 Start Pin 11 Start Pin 14 Start Pin 16 Start Pin 17 Start Pin 18 Start Pin 3 Start Pin 8 Start Pin 11 Start Pin 14 Start Pin 14 Start Pin 5 Start Pin 11 Start Pin 15 Start Pin 15 Start Pin 16 Start Pin 4 Start Pin 11 Start Pin 15 Start Pin 16 Start Pin 17 Start Pin 18 Start Pin 5 Turns 26t 1t 2t 4t 3t 6t 26t 7t 1t 2t 2t 26t 1t 2t 2t 4t 26t 1t 2t 4t 3t 6t 26t Wire size 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25mm 0.25mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm 0.25 mm Finish Pin Finish Pin 3 Finish Pin 14 Finish Pin 12 Finish Pin 10 Finish Pin 16 Finish Pin 17 Finish Pin 1 Finish Pin 9 Finish Pin 14 Finish Pin 12 Finish Pin 12 Finish Pin 4 Finish Pin 15 Finish Pin 13 Finish Pin 13 Finish Pin 10 Finish Pin 1 Finish Pin 15 Finish Pin 13 Finish Pin 10 Finish Pin 16 Finish Pin 17 Finish Pin 4 7.4 Transformer Sources For information on the vendors used to source the transformers used on this board, please visit the Power Integrations' Web site at the URL below and select "Engineering Prototype Boards" http://www.powerint.com/componentsuppliers.htm Power Integrations, Inc. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com Page 14 of 56 08-May-2001 EPR-000013 EPR-000013 43 W Multiple Output TOP246 Power Supply 8 Transformer Spreadsheets 8.1 230 VAC, 60 W Peak Load ACDC_TOPGX_Rev1.1_040401 Copyright Power Integrations Inc. 2000 INPUT INFO OUTPUT UNIT ENTER APPLICATION VARIABLES TOP_GX_040401.xls: TOPSwitch-GX Continuous/Discontinuous Flyback Transformer Design Spreadsheet Customer VACMIN 180 Volts Minimum AC Input Voltage VACMAX 265 Volts Maximum AC Input Voltage fL 50 Hertz AC Mains Frequency VO 3.3 Volts Output Voltage PO 60 Watts n 0.7 Z 0.5 VB 12 tC 3 CIN Output Power Efficiency Estimate Loss Allocation Factor Volts mSeconds Bridge Rectifier Conduction Time Estimate µFarads 68 Bias Voltage Input Filter Capacitor ENTER TOPSwitch-GX VARIABLES TOP-GX TOP246 Chosen Device Universal Power Out 90 W 115 Doubled/230 V ILIMITMIN 1.944 Amps 150 W External ILIMIT reduction factor (KI=1.0 for default ILIMIT, KI