EVALHVLED805

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. November 2011 Doc ID 18457 Rev 2 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 $,1      5 N    *1' ,/('   +9/(' 6285& ( 6285& ( '0* &203  5 N & Q & Q & Q 5 N 5  5  ".W 1.1 Efficiency measurement Figure 2. Efficiency measurement with one, two or three LEDs   (IILFLHQF\>@    9DF 9DF 9DF           9287>9@ !-V The efficiency is always higher than 70 % when two or three LEDs are connected, whereas it drops with one LED. The reason is that at low output voltage, the auxiliary voltage is not able to supply the IC and the internal HV current generator self supplies the Vcc pin, thus dissipating a power proportional to VIN. The output current has been measured with two or three LEDs which obtain an accuracy always below 5 %. 2/9 Doc ID 18457 Rev 2 EVALHVLED805 Figure 3. Electrical schematic Output current characteristics  2XWSXWFXUUHQW>P$@    9DF 9DF 9DF          2XWSXWYROWDJH>9@ !-V Figure 4. Start up at 230 VAC, 3 LEDs Figure 5. Doc ID 18457 Rev 2 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 2 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 2 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 Rev04 Flyback transformer Magnetica IC HVLED805 Primary switching regulator STMicroelectronics If not otherwise specified, all resistors are 5%, ¼ W Doc ID 18457 Rev 2 EVALHVLED805 Electrical schematic Table 2. Transformer characteristics Manufacturer Magnetica Part number 1921.0013 Rev. 04 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% 123:16 Primary to auxiliary turn ratio 5.59 ± 5% 123:22 Primary saturation current 0.21AP max (BSAT=0.35 T) Insulation primary-secondary 4 kV Figure 11. Transformer electrical scheme and dimensions (OHFWULFDOVFKHPH        %RWWRPYLHZ   ".W Doc ID 18457 Rev 2 7/9 Revision history 2 EVALHVLED805 Revision history Table 3. 8/9 Document revision history Date Revision Changes 09-Feb-2011 1 First release 16-Nov-2011 2 Updated Figure 1, Table 1, Table 2, Figure 9, Figure 11 Doc ID 18457 Rev 2 EVALHVLED805 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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