EVALHVLED805 4.2 W off-line LED driver with primary side regulation Data brief Features ■ Input voltage range (VIN): 185 - 265 VAC ■ Main frequency (fL): 50 - 60 Hz ■ Maximum (rated) output power: 4.2 W ■ Output: IOUT = 350 mA ± 5% – Over voltage = 12 V max – Current ripple < 10% IOUT ■ Minimum switching frequency in normal mode: 70 kHz ■ Target average efficiency (from 1 to 3 LEDs) > 70 % ■ Maximum input power in no-load < 100 mW Description The EVALHVLED805 is a demonstration board equipped with the new HVLED805 PWM current mode LED driver and is designed for European mains. It can control, with very good accuracy, from 1 to 3 LEDs having a nominal current of 350 mA. The HVLED805 has integrated high voltage startup and an 800 V power MOSFET. The high MOSFET's breakdown voltage allows very robust and reliable applications and reduces the size of the snubber and the relative power dissipation. Its accurate primary-current control eliminates the need of the optocoupler which impacts the cost, the compactness and the lifetime of the application while still maintaining a very good LED accuracy (below 5 %). Moreover, this converter, specifically designed for quasiresonant (QR) flyback converters, enables very low turn-on losses and EMI emissions. February 2011 Doc ID 18457 Rev 1 For further information contact your local STMicroelectronics sales office. 1/9 www.st.com 9 Electrical schematic 1 EVALHVLED805 Electrical schematic Figure 1. EVALHVLED805 electrical schematic / X 7 )O\ EDFN 7UDVI R ' 6736+$ - 9P$ ' 0%65& & Q) 5 N & X & X & X 5 N & X ' 677+/$ 5 - 9DF & Q ' 5 // & X 9&& 8 '5 $,1 '5 $,1 '5 $,1 '5 $,1 5 N *1' ,/(' +9/(' 6285& ( 6285& ( '0* &203 5 N & Q & Q & Q 5 N 5 5 ".W 1.1 Efficiency measurement Figure 2. Efficiency measurement with one, two or three LEDs (IILFLHQF\>@ 9DF 9DF 9DF 9287>9@ !-V The efficiency is always higher than 70 % when two or three LEDs are connected, whereas it drops with one LED. The reason is that at low output voltage, the auxiliary voltage is not able to supply the IC and the internal HV current generator self supplies the Vcc pin, thus dissipating a power proportional to VIN. The output current has been measured with two or three LEDs which obtain an accuracy always below 5 %. 2/9 Doc ID 18457 Rev 1 EVALHVLED805 Figure 3. Electrical schematic Output current characteristics 2XWSXWFXUUHQW>P$@ 9DF 9DF 9DF 2XWSXWYROWDJH>9@ !-V Figure 4. Start up at 230 VAC, 3 LEDs Figure 5. Doc ID 18457 Rev 1 Start up at 230 VAC, 1LEDs 3/9 Electrical schematic EVALHVLED805 Figure 6. Normal operation at 230 VAC, 3 LEDs Figure 8. Normal operation at 230 VAC: 1 LEDs 4/9 Figure 7. Doc ID 18457 Rev 1 Normal operation at 230 VAC, 2 LEDs EVALHVLED805 Figure 9. Electrical schematic PCB top side and through hole components (not in scale) ".W Figure 10. PCB: bottom side and SMD components (not in scale) ".W Doc ID 18457 Rev 1 5/9 Electrical schematic Table 1. Reference Note: 6/9 EVALHVLED805 Bill of material Part Description Note R1 22 Ω 1 W - Axial flame proof R2 120 kΩ R3 33 kΩ R4 5.6 kΩ R5 10 Ω R6 10 kΩ R7 3.3 kΩ 1% tolerance R8 10 Ω 1% tolerance R9 100 kΩ C1, C2 2.2 µF 400 V electrolytic C3 1 nF 500 V - XR7 C4 2.2 uF 35 V electrolytic C5 1 nF 25 V C6 470 nF 25 V C7 4.7 nF 25 V C8, C9 B41889A3108M 100 µF 16V electrolytic Rubycon ZLH C10 Y1- Capacitor 2.2 nF 230V D1 STTH1L06A Ultra-fast high voltage diode STMicroelectronics D2 LL4148 Small signal diode D3 STPS1H100A Power schottky diode STMicroelectronics L1 B78108S1474J 470µH axial inductor Epcos BR MB6S RC Input bridge rectifier TF 1921.0013 Rev.2 Flyback transformer Magnetica IC HVLED805 Primary switching regulator STMicroelectronics If not otherwise specified, all resistors are 5%, ¼ W Doc ID 18457 Rev 1 EVALHVLED805 Electrical schematic Table 2. Transformer characteristics Manufacturer Magnetica Part number 1921.0013 Rev. 2 Core E13 – N87 (or equivalent) Primary inductance 2.6mH ± 15% Air gap ˜ 70 µm Leakage inductance 1.42% nom Primary to secondary turn ratio 7.68 ± 5% (123 : 14) Primary to auxiliary turn ratio 5.59 ± 5% (123 : 19) Primary saturation current 0.21AP max (BSAT=0.35 T) Insulation primary-secondary 4 kV Figure 11. Transformer electrical scheme and dimensions (OHFWULFDOVFKHPH 1SUL 1VHF 1DX[ %RWWRPYLHZ ".W Doc ID 18457 Rev 1 7/9 Revision history 2 EVALHVLED805 Revision history Table 3. 8/9 Document revision history Date Revision 09-Feb-2011 1 Changes First release Doc ID 18457 Rev 1 EVALHVLED805 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2011 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com Doc ID 18457 Rev 1 9/9