Design Example Report Title 2.4W Power Supply using LNK520P Specification Input: 85 – 265 VAC Output: 5.0 V / 480 mA Application Cell Phone Charger Author Power Integrations Applications Department Document Number DER-38 Date April 28, 2004 Revision 1.0 Summary and Features • • • • • • • Low Cost, Low Component Count Design High Efficiency (> 70 %) at Full Load Accurate Output Voltage Regulation (using Opto-Coupler Feedback) Low Standby Consumption (< 250mW) Meets EMI Without Y-capacitor for Low Leakage Small Low Cost EE13 Transformer Universal input The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at www.powerint.com. Power Integrations 5245 Hellyer Avenue, San Jose, CA 95138 USA. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 Table Of Contents 1 2 3 4 Introduction .................................................................................................................3 Power Supply Specification ........................................................................................4 Schematic ...................................................................................................................5 Circuit Description.......................................................................................................6 4.1 Input EMI Filtering................................................................................................6 4.2 LinkSwitch Primary ..............................................................................................6 4.3 Output Rectification .............................................................................................6 4.4 Output Feedback .................................................................................................6 4.5 No Load Consumption .........................................................................................6 5 PCB Layout.................................................................................................................7 6 Bill Of Materials...........................................................................................................8 Transformer Specification – 041604b ................................................................................9 6.1 Electrical Diagram................................................................................................9 6.2 Electrical Specifications .......................................................................................9 6.3 Materials ..............................................................................................................9 6.4 Transformer Build Diagram................................................................................10 6.5 Transformer Construction ..................................................................................10 7 Transformer Spreadsheets .......................................................................................11 8 Performance .............................................................................................................13 8.1 Efficiency ...........................................................................................................13 8.2 No-Load Input Power.........................................................................................13 8.3 Regulation .........................................................................................................14 8.4 Measurement Data ............................................................................................15 9 Waveforms................................................................................................................16 9.1 Drain Voltage and Current, Normal Operation...................................................16 9.2 Load Transient Response (75% to 100% Load Step)........................................17 9.3 Output Ripple Measurements ............................................................................18 9.3.1 Ripple Measurement Technique.................................................................18 9.3.2 Measurement Results.................................................................................19 10 Conducted EMI .....................................................................................................20 11 Revision History ....................................................................................................22 Important Note: Although this board is designed to satisfy safety isolation requirements, the engineering prototype has not been agency approved. Therefore, all testing should be performed using an isolation transformer to provide the AC input to the prototype board. Design Reports contain a power supply design specification, schematic, bill of materials, and transformer documentation. Performance data and typical operation characteristics are included. Typically only a single prototype has been built. Page 2 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 1 Introduction This document is an engineering report describing a prototype cell phone power supply utilizing a LNK520P. This power supply is intended as a general purpose evaluation platform for this LinkSwitch device. The document contains the power supply specification, schematic, bill of materials, transformer documentation, printed circuit layout, and performance data. Figure 1 – Populated Circuit Board Photograph. Page 3 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 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 Total Output Power Continuous Output Power Peak Output Power Efficiency Symbol Min Typ Max Units Comment VIN fLINE 85 47 265 64 0.3 VAC Hz W 2 Wire – no P.E. 50/60 VOUT1 VRIPPLE1 IOUT1 5.5 5.0 4.5 V mV mA POUT POUT_PEAK η 380 480 580 2.4 W W % 70 ± 5% 20 MHz bandwidth ± 25% o Measured at POUT (43 W), 25 C Environmental Conducted EMI Meets CISPR22B / EN55022B Designed to meet IEC950, UL1950 Class II Safety Surge 2 kV Surge 2 kV Ambient Temperature 0 TAMB 50 o C 1.2/50 µs surge, IEC 1000-4-5, Series Impedance: Differential Mode: 2 Ω Common Mode: 12 Ω 100 kHz ring wave, 500 A short circuit current, differential and common mode Free convection, sea level Regualtion Specification 7 6 Voltage (V) 5 4 MIN MAX 3 2 1 0 0 100 200 300 400 500 600 Load (mA) Page 4 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 3 Schematic Figure 2 – Schematic. Page 5 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 4 Circuit Description 4.1 Input EMI Filtering Resistor RF1 acts as a fuse for the entire power supply and also limits different surge. Diodes D1, D3, D5, D7 and Capacitors C5, C6 rectify and filter the input waveform to produce a high voltage DC-bus. Inductors L1 and L3 work in conjunction with C5 and C6 to filter and attenuate conducted EMI. 4.2 LinkSwitch Primary Diode D10 and capacitor C12 rectify and filter the bias voltage. The diode is in a low-side configuration to allow the bias-winding to act as a primary cancellation winding. Components C3, R3, R4, and D4 form an RCD clamp to capture the leakage spike at Drain turn-off. A slow diode (D4) is used to allow recovery of some of this leakage inductance energy. The remainder is captured in C3 and dissipated in R3. 4.3 Output Rectification Output diode D2 and capacitor C7 rectify and filter the output voltage. 4.4 Output Feedback Resistor R9 is used to bias the Zener reference (VR1), adjusting this resistor will adjust the output voltage. Resistor R10 is used to control the opto-coupler current, and depending on the value can also change the output voltage set-point. The opto-coupler U2 transfers the feedback signal across the isolation barrier to the primary side of the supply. Resistor R6 set’s the maximum power point before the supply transitions into constant current mode. 4.5 No Load Consumption No-load consumption is affected by the choice of bias winding components. Use of a slow diode (1N4005GP) makes no-load consumption worse (by about 50mW at low-line), but gives the best CC regulation. Use of a fast diode D6 (such as 1N914) on the bias winding dramatically improves no-load consumption. However use of a fast diode also makes the constant-current (CC) regulation significantly non-linear. The absence of an RC snubber on the bias-winding, slightly improves the no-load consumption (10mW at lowline). Also the choice of Zener current setting resistor R9 affects the no-load consumption (again by approx 10mW at low-line). The value of resistor R7 has no effect on the no-load consumption. The set-point of the output voltage has a significant effect on the no-load consumption (high output voltage, higher no-load consumption) – e.g. going from Vout = 5.44 V to Vout = 6.5 V, the no-load consumption increased by 50mW. Page 6 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 5 PCB Layout Figure 3 – Printed Circuit Layout. Page 7 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 6 Bill Of Materials Item Quantity 1 2 3 4 5 Part Reference Description CAP 470pF 100V CERM CHIP X7R 1 C3 0805 SMD Cap,Al Elect,4.7uF,400V,8mmX11.5mm,Sam 2 C5 C6 Young Cap,Al Elect,330uF,16V,8mmX11.5mm,KZE 1 C7 Series,NIPPON CHEMI-CON CAP 0.22uF 25V CERM CHIP X7R 0805 1 C10 SMD 20-00205-00 Mfg Part Number ECUV1H471KBN 20-00434-00 SHD400WV 4.7uF Part Number 20-00014-00 20-00237-00 Cap,Cer, 1.0 uF, 50V, 10% 20-00308-00 6 7 8 10 11 1 C12 D1 D3 D5 5 D7 D10 1 D2 1 D4 2 J1 J2 2 J3 J4 Rectifier GPP 600V 1A DO-41 Diode Schottky 60V 1.1A DO-41 Rectifier GPP 1000V 1A DO-41 Terminal,1Pin,22AWG Terminal,1Pin,18AWG 15-00089-00 15-00153-00 TMP-59 35-00008-00 35-00007-00 12 12 2 L1 2 L3 CHOKE,1mH,SBCP_47HY102B,TOKIN 30-00018-00 CHOKE,FERRITE BEAD 13 1 R3 Res,150K 1/16W 5% 0603 SMD 05-01740-00 14 15 1 R4 1 R6 Res,300 1/10W 5% 0805 SMD Res,7.50K 1/16W 1% 0603 SMD 05-01506-00 05-01162-00 16 1 R7 Res,15 1/16W 5% 0603 SMD 05-01644-00 17 1 R9 Res,680 1/16W 5% 0603 SMD 05-01684-00 18 1 R10 Res,120 1/16W 5% 0603 SMD 05-01666-00 19 20 1 RF1 1 T1 05-02802-00 25-00061-00 21 1 U1 22 23 1 U2 1 VR1 Res, 8.2 ,1W, 5%, Metal Film BEE16_H_LOPROFILE_10P IC,LNK 520P,CV or CV/CC SWITCHER,PLAS,DIP-8B IC,PC817D,PHOTOCOUPLER TRAN OUT 4-DIP DIODE ZENER 4.7V 500MW MINIMELF Page 8 of 23 KZE16VB331MH 11LL ECJ2YB1E224K ECUS1H105KBB 1N4005-T 11DQ06 1N4007GDICT SBCP_47HY102 B ERJ3GEYJ154V ERJ6GEYJ301V ERJ-3EKF7501V ERJ3GEYJ150V ERJ3GEYJ681V ERJ3GEYJ121V RSF200JB0R8.2 TMP-111 LNK520P 45-00008-00 15-00188-00 PC817D ZMM5230B-7 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 Transformer Specification – 041604b 6.1 Electrical Diagram 2 1 W1: 39T 1 x 34 AWG 7 3 W2: 114T 1 x 35 AWG W4: 12T 1 x 26 TIW 4 8 3 W3: 13T 2 x 31 AWG FL1 Figure 4 –Transformer Electrical Diagram 6.2 Electrical Specifications Electrical Strength Primary Inductance Resonant Frequency Primary Leakage Inductance 6.3 1 second, 60 Hz, from Pins 2-1,3-4 to Pins 6-5 Pins 4-3, all other windings open, measured at 100 kHz, 0.4 VRMS Pins 4-3, all other windings open Pins 4-3 with Pins 7-8 shorted, measured at 100 kHz, 0.4 VRMS 3000 VAC 2390 µH, 0/+20% 300 kHz (Min.) 100 µH (Max.) Materials Item [1] [2] [3a] [3b] [3c] [3d] [4a] [6] Core: TDK PC40 EE13, AL = 185 nH/T2 Bobbin: EE13 Horizontal Magnet Wire: 34 AWG Magnet Wire: 35 AWG Magnet Wire: 31 AWG Triple Insulated Wire: 26 AWG (TIW) Tape Varnish Page 9 of 23 Description Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 6.4 2.4W Power Supply using LNK520P April 28, 2004 Transformer Build Diagram 8 7 3 W4 Tape W3 Shield FL1 Floating 3 Tape W2 Primary 4 Tape 2 1 W1 Cancellation Figure 5 – Transformer Build Diagram. 6.5 Transformer Construction Shield 1 Basic Insulation Primary Basic Insulation Shield 2 Basic Insulation Secondary Winding Outer Wrap Final Assembly Page 10 of 23 Start at Pin 1. Wind 39 turns of item [3a] in approximately 1 layer. Finish at Pin 2. Use two layers of item [6] for basic insulation. Start at Pin 4. Wind 114 turns of item [3b] in approximately 3 layers. After 1st layer insert one layer of tape. Complete 2nd layer insert one layer of tape. Complete 3rd layer. Finish at Pin 3. Use two layers of item [6] for basic insulation. Temporary start at Pin 2. Wind 13 turns of bifilar item [3c]. Spread turns evenly across bobbin. Finish at Pin 3. (Disconnect from pin 2 and leave floating (FL1) in the stack.) Use one layer of item [7] for basic insulation. Temporary start at pin 2. Wind 12 turns of item [3d] in 1 layer. Finish on Pin 8. Move connection from pin 2 to pin 7. Wrap windings with 3 layers of tape [item [4a]. Assemble and secure core halves. Varnish dip (item [6]). Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 7 Transformer Spreadsheets LinkSwitch (LNK52X) 030404; Rev.1.7; Copyright Power Integrations 2004 INPUT INFO LinkSwitch (LNK52X) 030404 Rev.1.7; Copyright Power Integrations 2004 OUTPUT UNIT ENTER APPLICATION VARIABLES VACMIN VACMAX fL VO IO DI-75 - 042304A 85 265 50 5 0.48 VBIAS tC CIN 20 3 9.4 Volts Volts Hertz Volts Amps Minimum AC Input Voltage Maximum AC Input Voltage AC Mains Frequency Output Voltage Continuous Nominal Output current msec uFarads Bias voltage (recommended default 20V, minimum 16V) Bridge Rectifier Conduction Time Estimate Input Filter Capacitor ESTIMATED LOSSES PCORE 146.3907 mW RCLAMP ESR 200 Kohm 0.15 Ohms RSEC 0.2 Ohms Estimated Core Losses at peak Flux Density (BP) Primary clamp resistor (recommended default clamp resistor, RCLAMP) Output Capacitor ESR Estimated Resistance of transformer secondary winding. DC INPUT VOLTAGE PARAMETERS VMIN VMAX 97.50129 Volts 374.7666 Volts Minimum DC Input Voltage Maximum DC Input Voltage ENTER OUTPUT CABLE PARAMETERS RCABLE VCABLE 0.3 Ohms 0.144 Volts Resistance of total length of cable from power supply terminals to load and back. Drop along cable connecting power supply to load ENTER LinkSwitch & OUTPUT DIODE VARIABLES LinkSwitch LNK520 I^2 f VOR 54 VLEAK Universal 115 Doubled/230 Power 5.5 3.5 I^2 f (typical) co-efficient for LinkSwitch 2710 A^2 Hz 54 Volts 2 Volts VD 0.56 VR ID 1.1 0.56 Volts 60 Volts Amps Reflected Output Voltage (40<VOR<80 recommended) Error in Feedback voltage as a result of leakage inductance in primary circuit. Output Winding Diode Forward Voltage Drop (0.5~0.7V for schottky and 0.7~1.0V for PN diode) Rated Peak Rep Reverse Voltage of secondary diode Rated Average Forward current for secondary diode DISCONTINUOUS MODE CHECK KDP TON TDON 1.531793 6.587284 us 11.24319 us Ensure KDP > 1.15 for discontinuous mode operation. Linkswitch conduction time Secondary Diode conduction time VOLTAGE STRESS ON LinkSWITCH AND OUTPUT DIODE VDRAIN PIVS 508.1666 Volts 44.58646 Volts Maximum Drain Voltage Estimate (Includes Effect of Leakage Inductance) Output Rectifier Maximum Reverse Voltage 0.276666 0.035137 Amps 0.077135 Amps Maximum Operating Duty Cycle Average Primary Current Primary RMS Current CURRENT WAVEFORM SHAPE PARAMETERS DMAX IAVG IRMS Page 11 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 ENTER TRANSFORMER CORE/CONSTRUCTION VARIABLES Core Type Core Bobbin AE LE AL VE BW KCORE EE13 T(n) M NS PC40EE13-Z BE-13 0.171 3.02 1130 517 7.4 551.5424 0.9 Core Effective Cross Sectional Area Core Effective Path Length Ungapped Core Effective Inductance Effective Core Volume Bobbin Physical Winding Width Core losses per unit volume Estimated transformer efficiency. T(n)=(PSCU+PCORE/2)/POEFF. Re-iterate with n = 0.9147 Safety Margin Width Number of Secondary Turns cm^2 cm nH/T^2 mm^3 mm kW/m^3 0.9 0 mm 12 TRANSFORMER PRIMARY DESIGN PARAMETERS dLP LP L LBIAS NP NB ALG BP LG OD DIA 3 1 1.003 2390.284 3 1 113.6045 36.28176 185.2075 3445.212 0.097008 nH/T^2 Gauss mm 0.195415 mm 0.154132 mm AWG CMA AWG_BIAS uHenries 35 AWG Constant to account for reduction of inductance at higher flux densities. (0.999<dLP<1.05) Primary Inductance Number of Primary Layers Number of Bias winding Layers Primary Winding Number of Turns Gapped Core Effective Inductance Peak Flux Density (BP<3700) Core Gap Length for primary inductance Maximum Primary Wire Diameter including insulation to give specified number of layers. Bare conductor diameter Primary Wire Gauge (Rounded to next smaller standard AWG value) 414.8576 Cmils/Amp Primary Winding Current Capacity (200 < CMA < 500) 32 AWG TRANSFORMER SECONDARY DESIGN PARAMETERS ISP ISRMS IRIPPLE 2.404628 Amps 0.954018 Amps 0.82447 Amps AWGS DIAS 30 AWG 0.256342 mm Peak Secondary Current Secondary RMS Current Output Capacitor RMS Ripple Current Secondary Wire Gauge (Rounded up to next larger standard AWG value) Secondary Minimum Bare Conductor Diameter ODS INSS VSEC 0.616667 mm 0.180162 mm 0.096 Volts Secondary Maximum Insulated Wire Outside Diameter Maximum Secondary Insulation Wall Thickness Voltage Drop across secondary winding 7.065217 k-Ohms 37.375 mW Feedback resistor Losses in the Feedback resistor FEEDBACK CIRCUIT COMPONENTS RFB PRFB ESTIMATED LOSSES IN POWER SUPPLY AND EFFICIENCY, LOW LINE PCABLE PSCU PDIODE PCAP PBIAS 69.12 182.0302 268.8 136.5226 50.6 mW mW mW mW mW Power loss in Output Cable Transformer Secondary Copper Losses Output Diode conduction loss PCONDUCTION PCLAMP PCORE PBRIDGE EFFICIENCY ESTIMATE 249.8913 14.58 146.3907 32.93465 67.58908 mW mW mW mW % Conduction Losses in LinkSwitch calculated at 100C Primary clamp losses Core Losses at peak Flux Density Primary bridge rectifier losses Estimated Power Supply Efficiency Volts Volts Auxiliary Output Voltage Auxiliary Diode Forward Voltage Drop Auxiliary Number of Turns Auxiliary Rectifier Maximum Peak Inverse Voltage Power Loss in Feedback circuit ADDITIONAL OUTPUT VX VDX NX PIVX Page 12 of 23 0 0 Volts Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 8 Performance 8.1 Efficiency Efficiency vs Load - 042304a Efficiency (%) 80.00% 70.00% 85VAC 115VAC 230VAC 265VAC 60.00% 50.00% 0 100 200 300 400 500 Load (mA) Figure 6- Efficiency vs. Input Voltage, Room Temperature, 60 Hz. 8.2 No-Load Input Power No Load Consumption - 042304a 0.30 0.25 Pin (W) 0.20 0.15 No Load 0.10 0.05 0.00 60 90 120 150 180 210 240 270 Vin (VAC) Figure 7 – Zero Load Input Power vs. Input Line Voltage, Room Temperature, 60 Hz. Page 13 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 8.3 2.4W Power Supply using LNK520P April 28, 2004 Regulation Regulation - 042304a 7 6 Voltage (V) 5 MIN MAX 4 85 VAC 115 VAC 3 230 VAC 2 265 VAC 1 0 0 100 200 300 400 500 600 Load (mA) Figure 8 –Line and Load Regulation, Room Temperature. Page 14 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 8.4 2.4W Power Supply using LNK520P April 28, 2004 Measurement Data Vin Pin Vout Iout Pout 0.153 0.792 1.479 2.268 3.492 2.82 2.484 1.995 1.56 0.138 0.132 5.46 5.37 5.32 5.27 5.19 4.46 3.76 2.891 2.041 0.203 0.005 0 100 202 313 479 451 465 472 492 64 75 115.67 115.71 115.71 115.41 115.38 115.39 115.59 115.39 115.59 115.81 115.71 115.67 0.162 0.798 1.491 2.139 2.931 3.438 2.529 2.37 1.959 1.41 0.162 0.156 5.47 5.38 5.34 5.3 5.25 5.21 4.26 3.93 3.114 1.939 0.209 0.006 0 0 0 100 0.538 0.674185 203 1.08402 0.727042 298 1.5794 0.738382 410 2.1525 0.734391 481 2.50601 0.728915 431 1.83606 0.726002 435 1.70955 0.721329 440 1.37016 0.699418 468 0.907452 0.643583 66 0.013794 0.085148 73 0.000438 0.002808 230.43 230.47 230.66 230.56 229.95 230.33 230.21 230.35 230.49 230.35 230.44 0.219 0.843 1.539 2.196 2.955 3.759 2.547 1.956 1.425 0.246 0.243 5.46 5.39 5.35 5.31 5.27 5.22 4.05 2.84 1.908 0.173 0.005 0 0 0 100 0.539 0.639383 203 1.08605 0.705686 297 1.57707 0.718156 410 2.1607 0.731201 527 2.75094 0.731828 447 1.81035 0.710777 463 1.31492 0.672249 458 0.873864 0.613238 54 0.009342 0.037976 65 0.000325 0.001337 265.2 265.62 265.83 265.41 265.17 265.9 265.65 265.33 265.38 266.04 265.74 265.48 0.237 0.882 1.566 2.22 2.988 3.798 2.775 2.532 2.121 1.533 0.285 0.288 5.46 5.38 5.35 5.31 5.27 5.22 4.22 3.77 2.94 1.96 0.181 0.006 0 0 0 99 0.53262 0.603878 204 1.0914 0.696935 298 1.58238 0.712784 410 2.1607 0.723126 528 2.75616 0.725687 466 1.96652 0.708656 466 1.75682 0.693847 480 1.4112 0.665347 471 0.92316 0.602192 55 0.009955 0.03493 75 0.00045 0.001563 Page 15 of 23 0 0.537 1.07464 1.64951 2.48601 2.01146 1.7484 1.364552 1.004172 0.012992 0.000375 Eff 86.05 86.07 85.95 85.77 85.65 85.85 85.77 85.93 86.01 86.19 86.13 0 0.67803 0.726599 0.727297 0.711916 0.713284 0.703865 0.683986 0.6437 0.094145 0.002841 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P 9 Waveforms 9.1 Drain Voltage and Current, Normal Operation Figure 9 - 85 VAC, Full Load (5.13 V/ 484 mA). Upper: VDRAIN, 200 V / div, Lower: IDRAIN, 0.1 A , 5 µs / div Page 16 of 23 April 28, 2004 Figure 10 - 265 VAC, Full Load (5.19 V/ 490 mA) Upper: VDRAIN, 200 V / div, Lower: IDRAIN, 0.1 A , 5 µs / div Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P 9.2 Load Transient Response (75% to 100% Load Step) In the figures shown below, no signal averaging was used. triggered using the load current step as a trigger source. Figure 11 – Transient Response, 115 VAC, 75-10075% Load Step. Top: Output Voltage, 200 mV/div. Bottom: Load Current 200 mA, 2ms / div. Page 17 of 23 April 28, 2004 The oscilloscope was Figure 12 – Transient Response, 230 VAC, 75-10075% Load Step. Top: Output Voltage, 200 mV/div. Bottom: Load Current 200 mA, 2ms / div. Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 9.3 2.4W Power Supply using LNK520P April 28, 2004 Output Ripple Measurements 9.3.1 Ripple Measurement Technique For DC output ripple measurements, a modified oscilloscope test probe must be utilized in order to reduce spurious signals due to pickup. Details of the probe modification are provided in Figure 15 and Figure 16. The 5125BA probe adapter is affixed with two capacitors tied in parallel across the probe tip. The capacitors include one (1) 0.1 µF/50 V ceramic type and one (1) 1.0 µF/50 V aluminum electrolytic. The aluminum electrolytic type capacitor is polarized, so proper polarity across DC outputs must be maintained (see below). Probe Ground Probe Tip Figure 13 - Oscilloscope Probe Prepared for Ripple Measurement. (End Cap and Ground Lead Removed) Figure 14 - Oscilloscope Probe with Probe Master 5125BA BNC Adapter. (Modified with wires for probe ground for ripple measurement, and two parallel decoupling capacitors added) Page 18 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 9.3.2 Measurement Results Figure 15 - Ripple, 85 VAC, Full Load. 2 ms, 50 mV / div Figure 16 - 5 V Ripple, 115 VAC, Full Load. 2 ms, 50 mV / div Figure 17 - Ripple, 230 VAC, Full Load. 2 ms, 50 mV /div Page 19 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 10 Conducted EMI Figure 26 - Conducted EMI, Maximum Steady State Load, 115 VAC, 60 Hz, and EN55022 B Limits – Ungrounded Secondary. Figure 26 - Conducted EMI, Maximum Steady State Load, 115 VAC, 60 Hz, and EN55022 B Limits – Grounded Secondary Page 20 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 Figure 27 - Conducted EMI, Maximum Steady State Load, 230 VAC, 60 Hz, and EN55022 B Limits Ungrounded Secondary Figure 27 - Conducted EMI, Maximum Steady State Load, 230 VAC, 60 Hz, and EN55022 B Limits Ungrounded Secondary Page 21 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 11 Revision History Date April 28, 2004 Page 22 of 23 Author RM Revision 1.0 Description & changes Initial release Reviewed VC / AM Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-38 2.4W Power Supply using LNK520P April 28, 2004 For the latest updates, visit our Web site: www.powerint.com Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your use of any information, device or circuit described herein nor does it convey any license under its patent rights or the rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS. PATENT INFORMATION The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at www.powerint.com. The PI Logo, TOPSwitch, TinySwitch, LinkSwitch, and EcoSmart are registered trademarks of Power Integrations. PI Expert and DPA-Switch are trademarks of Power Integrations. © Copyright 2004, Power Integrations. WORLD HEADQUARTERS Power Integrations 5245 Hellyer Avenue, San Jose, CA 95138, USA Main: +1-408-414-9200 Customer Service: Phone: +1-408-414-9665 Fax: +1-408-414-9765 e-mail: [email protected] CHINA (SHENZHEN) Power Integrations International Holdings, Inc. Rm# 1705, Bao Hua Bldg. 1016 Hua Qiang Bei Lu, Shenzhen, Guangdong, 518031, China Phone: +86-755-8367-5143 Fax: +86-755-8377-9610 e-mail: [email protected] ITALY Power Integrations s.r.l. Via Vittorio Veneto 12, Bresso, Milano, 20091, Italy Phone: +39-028-928-6001 Fax: +39-028-928-6009 e-mail: [email protected] SINGAPORE (ASIA PACIFIC HEADQUARTERS) Power Integrations, Singapore 51 Newton Road, #15-08/10 Goldhill Plaza, Singapore, 308900 Phone: +65-6358-2160 Fax: +65-6358-2015 e-mail: [email protected] AMERICAS Power Integrations, Inc. 4335 South Lee Street, Suite G, Buford, GA 30518, USA Phone: +1-678-714-6033 Fax: +1-678-714-6012 e-mail: [email protected] GERMANY Power Integrations, GmbH Rueckertstrasse 3, D-80336, Munich, Germany Phone: +49-895-527-3910 Fax: +49-895-527-3920 e-mail: [email protected] JAPAN Power Integrations, K.K. Keihin-Tatemono 1st Bldg. 12-20 Shin-Yokohama, 2-Chome, Kohoku-ku, Yokohama-shi, Kanagawa 222-0033, Japan Phone: +81-45-471-1021 Fax: +81-45-471-3717 e-mail: [email protected] TAIWAN Power Integrations International Holdings, Inc. 17F-3, No. 510, Chung Hsiao E. Rd., Sec. 5, Taipei, Taiwan 110, R.O.C. Phone: +886-2-2727-1221 Fax: +886-2-2727-1223 e-mail: [email protected] CHINA (SHANGHAI) Power Integrations International Holdings, Inc. Rm 807, Pacheer, Commercial Centre, 555 Nanjing West Road, Shanghai, 200041, China Phone: +86-21-6215-5548 Fax: +86-21-6215-2468 e-mail: [email protected] INDIA (TECHNICAL SUPPORT) Innovatech 261/A, Ground Floor 7th Main, 17th Cross, Sadashivanagar Bangalore, India, 560080 Phone: +91-80-5113-8020 Fax: +91-80-5113-8023 e-mail: [email protected] KOREA Power Integrations International Holdings, Inc. 8th Floor, DongSung Bldg. 17-8 Yoido-dong, Youngdeungpo-gu, Seoul, 150-874, Korea Phone: +82-2-782-2840 Fax: +82-2-782-4427 e-mail: [email protected] UK (EUROPE & AFRICA HEADQUARTERS) 1st Floor, St. James’s House East Street Farnham, Surrey GU9 7TJ United Kingdom Phone: +44-1252-730-140 Fax: +44-1252-727-689 e-mail: [email protected] APPLICATIONS HOTLINE World Wide +1-408-414-9660 APPLICATIONS FAX World Wide +1-408-414-9760 ER or EPR template – Rev 3.5 – Single sided Page 23 of 23 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com