View DER-92_1232181.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Design Example Report
Title Specification Application Author Document Number Date Revision 0.5W Non-Isolated Buck-Boost Converter using the LNK302P Input: 85-265 VAC Output: 0.5W, 40mA Constant current LED Driver Power Integrations Applications Department DER-92 August 11, 2005 1.0
Summary and Features * * * * * * Low component count (only 9 components required) Low Cost, light weight, compact solution No Opto-Coupler required Open loop operation High efficiency (~70%) Meets EN55022 B EMI limits with > 8 dB margin
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-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
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-TN .....................................................................................................6 4.3 Output Rectification .............................................................................................6 4.4 Circuit Operation..................................................................................................6 5 PCB Layout.................................................................................................................7 6 Bill Of Materials...........................................................................................................8 7 Spreadsheet ...............................................................................................................9 8 Performance Data.....................................................................................................10 8.1 Efficiency ...........................................................................................................10 9 Waveforms................................................................................................................10 9.1 Drain Voltage and Current, Normal Operation...................................................10 9.2 Output Current, Normal operation......................................................................11 10 Conducted EMI .....................................................................................................12 11 Revision History ....................................................................................................13
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 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
1 Introduction
This document is an engineering report describing a 0.5 W constant current LED driver power supply utilizing a LNK302P. This power supply is intended as a LED driver that can be used in emergence exit signs and neon light replacements The document contains the power supply specification, schematic, bill of materials, printed circuit layout, and performance data.
Figure 1 - Populated Circuit Board Photograph
Page 3 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
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 Full Load Environmental Conducted EMI Safety Surge
Meets CISPR22B / EN55022B Designed to meet IEC950, UL1950 Class II
Symbol VIN fLINE
Min 85 47
Typ
Max 265 64
Units VAC Hz W V mV mA W W %
Comment
2 Wire - no P.E.
50/60 13 40 0.5 0.5 70
VOUT1 VRIPPLE1 IOUT1 POUT POUT_PEAK
5% 20 MHz bandwidth
Measured at POUT 25 C
o
kV
Surge Ambient Temperature TAMB 0 25 50
kV
o
1.2/50 s surge, IEC 1000-4-5, Series Impedance: Differential Mode: 2 Common Mode: 12 100 kHz ring wave, 500 A short circuit current, differential and common mode Free convection, sea level
C
Page 4 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
3 Schematic
Figure 2 - Schematic
Page 5 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
4 Circuit Description
This is a very simple circuit, which requires as few as 9 components. An additional input diode may be placed on the return leg for EMI and surge withstand capability 4.1 Input EMI Filtering Resistors RF1, RF2 and capacitors C1 and C2 form the EMI filter. C1 C2 and RF2 are connected to form a low cost resistive filter and provide excellent differential mode filtering and also serve as the stable DC bus voltage. Resistor RF1 is a fusible flameproof type while RF2 can be only flameproof. 4.2 LinkSwitch-TN LNK302P is used in open loop mode for this circuit. This particular device in the LinkSwitch-TN family does not have the auto restart feature, and thus when the feedback pin is left open, the MOSFET switches every cycle until current limit (or duty cycle limit) is reached. 4.3 Output Rectification Since this circuit operates strictly in the discontinuous conduction mode (DCM) a 75 nS recovery time UF4005 diode is used for output rectification. The buck boost topology also provides benefits of isolating the output from the input in case of Switch failure 4.4 Circuit Operation This LED driver operates at 66 kHz and energy is provided to the LED's every switching cycle. Since the circuit operates in discontinuous mode, a fixed amount of energy is stored each cycle in L2, then is completely transferred to the load (i.e. the LEDs). The current in the LED is a triangular waveform, whose peak is determined by the fixed and well-controlled current limit of the LNK302. The load current is thus independent of line voltage. As such the need for output filter capacitor is completely eliminated.
Page 6 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
5 PCB Layout
Figure 3 - Printed Circuit Layout
Page 7 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
6 Bill Of Materials
Item Quantity Reference Part 1 2 3 4 5 6 7 8 9 10 Description Manufacturer 400 V input 2 C1,C2 2.2 uF UCC capacitors 0.1 uF, 50 V (ECU- Bypass pin 1 C3 Panasonic S1H104KBB) capacitor Input rectifier Diodes Inc (or 1 D1 1N4007 diode Generic) Output rectifier Gen Semiconductor 1 D3 UF4005 diode (or generic) AC Input 2 J1,J2 CON1 Generic connector Super bright 12 LED1,...12 5mm OSRAM White LED's 1 L2 SBC1-102-211 1 mH inductor Tokin 1W, Fusible 1 RF1 8.2 Ohm 1W and Flameproof VTM 1 RF2 47 Ohm, Flameproof Flameproof VTM 1 U1 LNK302P LinkSwitch-TN Power Integrations
Page 8 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
7 Spreadsheet
ACD C_LinkS witch-T N _BuckBoost_042605; R e v.2.0; Copyright P owe r Inte gra tions 2004 IN P U T LinkSwitch-T N _BuckBoost_R e v2-0.xls: LinkS witch-T N D e sign S pre a dshe e t
IN FO
OU T P U T
U N IT Volts Volts Hertz Volts Amps
INPUT VARIABLES
VACMIN VACMAX FL VO IO EFFICIENCY (User Estimate) EFFICIENCY (Calculated Estimate) CIN Input Stage Resistance Ambient Temperature Input Rectification Type 85 265 50 12.50 0.035 0.75 4.40 8.2 H 0.65 4.40 8.2 50 H
Customer
Minimum AC Input Voltage Maximum AC Input Voltage Line Frequency Output Voltage Output Current Overall Efficiency Estimate (Adjust to match Calculated, or enter Measured Efficiency) Calculated % Efficiency Estimate uF Input Filter Capacitor ohms Input Stage Resistance, Fuse & Filtering deg C Operating Ambient Temperature (deg Celcius) Choose H for Half Wave Rectifier and F for Full Wave Rectification
DC INPUT VARIABLES
VMIN VMAX 99.7 374.8 Volts Minimum DC Bus Voltage Volts Maximum DC Bus Voltage
LINKSWITCH-TN
LINKSWITCH-TN ILIMIT ILIMIT_MIN ILIMIT_MAX FSMIN VDS PLOSS_LNK LNK302 0.136 0.136 0.146 66000 12.0 0.20 Amps Amps Amps Hertz Volts Watts Selected LinkSwitch-TN Typical Current Limit Minimum Current Limit Maximum Current Limit Minimum Switching Frequency Maximum On-State Drain To Source Voltage drop Estimated LinkSwitch-TN losses
DIODE
VD VRR IF TRR 0.70 600 1 75 Volts Volts Amps ns Freewheeling Diode Forward Voltage Drop Recommended PIV rating of Freewheeling Diode Recommended Diode Continuous Current Rating Recommended Reverse Recovery Time
Diode Recommendation
UF4005
Suggested Freewheeling Diode
OUTPUT INDUCTOR
L_TYP 989.2 Required value of Inductance to deliver Output Power (Includes device uH and inductor tolerances) Choose next higher standard available value
L
L_R
1000
2.0
uH Output Inductor, Recommended Standard Value
Ohms DC Resistance of Inductor
OPERATING MODE
KL_TOL K_LOSS ILRMS
DCM
1.15 0.833 0.06
Discontinuous Conduction Mode (at VMIN)
Amps Estimated RMS inductor current (at VMAX)
Page 9 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
8
8.1
Performance Data
Efficiency
Efficiency Vs Line Voltage
80 79 78 77 Efficiency 76 75 74 73 72 71 70 50 100 150 200 250 300 Line Voltage (V)
All measurements performed at room temperature, 60 Hz input frequency.
Figure 4 - Efficiency Vs Line Voltage
9 Waveforms
9.1 Drain Voltage and Current, Normal Operation
Figure 5 - 85 VAC, Full Load. Upper: IDRAIN, 50 mA / div Lower: VDRAIN, 50 V, 5 s / div
Figure 6 - 265 VAC, Full Load Upper: IDRAIN, 50 mA / div Lower: VDRAIN, 200 V / div, 2 s / div
Page 10 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92 9.2
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
Output Current, Normal operation
Figure 7 - 115VAC 50 ms / div. 5 s / div
Figure 8 - Start-up Profile, 230 VAC 50 ms / div. 2 s / div
Page 11 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
10 Conducted EMI
Figure 9 - Conducted EMI, Maximum Steady State Load, foreground shows 230 VAC, background shows 115 VAC, 60 Hz, and EN55022 B Limits.
Page 12 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
11 Revision History
Date Author August 11, 2005 SK Revision 1.0 Description & changes First Draft Reviewed AM / VC
Page 13 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com
DER-92
0.5W, 40mA, Open Loop LED Driver
August 11, 2005
For the latest updates, visit our website: 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, T OPSw it c h, T i nySw it c h , Li nk Sw i t c h , DPA-Sw i t c h and Ec oSm ar t are registered trademarks of Power Integrations. PI Ex pert and PI FA CTS are trademarks of Power Integrations. (c) Copyright 2005 Power Integrations.
Power Integrations Worldwide Sales Support Locations
WORLD HEADQUARTERS 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: usasales@powerint.com GERMANY Rueckerstrasse 3 D-80336, Muenchen Germany Phone: +49-895-527-3910 Fax: +49-895-527-3920 e-mail: eurosales@powerint.com JAPAN 1st Bldg Shin-Yokohama, 2-12-20 Kohoku-ku, Yokohama-shi, Kanagawa ken, Japan 222-0033 Phone: +81-45-471-1021 Fax: +81-45-471-3717 e-mail: japansales@powerint.com KOREA RM 602, 6FL Korea City Air Terminal B/D, 159-6 Samsung-Dong, Kangnam-Gu, Seoul, 135-728, Korea Phone: +82-2-2016-6610 Fax: +82-2-2016-6630 e-mail: koreasales@powerint.com SINGAPORE 51 Newton Road, #15-08/10 Goldhill Plaza, Singapore, 308900 Phone: +65-6358-2160 Fax: +65-6358-2015 e-mail: singaporesales@powerint.com TAIWAN 5F-1, No. 316, Nei Hu Rd., Sec. 1 Nei Hu Dist. Taipei, Taiwan 114, R.O.C. Phone: +886-2-2659-4570 Fax: +886-2-2659-4550 e-mail: taiwansales@powerint.com
CHINA (SHANGHAI) Rm 807-808A, Pacheer Commercial Centre, 555 Nanjing West Rd. Shanghai, P.R.C. 200041 Phone: +86-21-6215-5548 Fax: +86-21-6215-2468 e-mail: chinasales@powerint.com
INDIA (TECHNICAL SUPPORT) 261/A, Ground Floor 7th Main, 17th Cross, Sadashivanagar Bangalore, India 560080 Phone: +91-80-5113-8020 Fax: +91-80-5113-8023 e-mail: indiasales@powerint.com
UK (EUROPE & AFRICA HEADQUARTERS) 1st Floor, St. James's House East Street, Fernham Surrey, GU9 7TJ United Kingdom Phone: +44 (0) 1252-730-140 Fax: +44 (0) 1252-727-689 e-mail: eurosales@powerint.com APPLICATIONS HOTLINE World Wide +1-408-414-9660 APPLICATIONS FAX World Wide +1-408-414-9760
CHINA (SHENZHEN) Room 2206-2207, Block A, Elec. Sci. Tech. Bldg 2070 Shennan Zhong Rd Shenzhen, Guangdong, China, 518031 Phone: +86-755-8379-3243 Fax: +86-755-8379-5828 e-mail: chinasales@powerint.com
ITALY Via Vittorio Veneto 12 20091 Bresso MI Italy Phone: +39-028-928-6000 Fax: +39-028-928-6009 e-mail: eurosales@powerint.com
Page 14 of 14
Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com

▲Up To Search▲

Price & Availability of DER-92

	To Download DER-92 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .