AN1916 Application note VIPower: Offline constant current LED driver using VIPer12/22A Introduction High brightness LEDs are becoming a prominent source of light and often have better efficiency and reliability when compared to that of conventional light sources. While LEDs can operate from an energy source as simple as a battery and resistor, most applications require an efficient energy source not only for the reduction of losses, but also for the lumen maintenance of the LED itself. Using integrated off line switching regulators like the VIPer12A and VIPer22A in a constant current configuration, a low cost, high efficient LED driver for multiple LEDs has been developed. This document introduces the isolated and non-isolated offline constant current LED driver based on the VIPerX2A family. All three LED driver configurations operate in the extended wide range input voltage, from 90 to 264Vac. VIPer12A and VIPer22A are low cost monolithic smart power devices with integrated PWM controllers. Their internal control circuit offers benefits such as automatic burst mode in low load condition, overvoltage protection in hiccup mode, and large voltage range on the VDD pin. An isolated VIPer12A constant current LED driver has been configured to drive 1 to 4 LEDs while the isolated VIPer22A configuration has been optimized for 2 to 8 LEDs. VIPer12A constant current LED driver board layout August 2006 Rev4 1/45 www.st.com Contents AN1916 Contents 1 LED parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 LED Intensity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 Design consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Board description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5 Transformer specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6 Current selectable reference board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 7 PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 8 General circuit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 10 EMI results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 11 Current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 12 Ripple current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 13 1.8" Round LED board configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 35 14 Round LED board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 15 EMI result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 16 Current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 17 Ripple current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 18 Low cost option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 2/45 AN1916 Contents 19 PCB layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 20 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 21 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3/45 List of figures AN1916 List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. 4/45 Current vs. LUX and VF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Mechanical characteristics of the transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 VIPer12A current selectable LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 VIPer22A current selectable LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 VIPer12A constant current (350mA) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . 17 VIPer22A constant current (350mA) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . 19 VIPer12A constant current (700mA) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . 21 VIPer22A constant current (700mA) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . 23 VIPer12A constant current (1.05A) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . . 25 VIPer22A constant current (1.05A) LED driver schematic . . . . . . . . . . . . . . . . . . . . . . . . . 27 Board top side (not in scale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Board bottom side viewed from top side (not in scale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 VIPer12A with 1 LED at output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VIPer12A with 4 LEDs at output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VIPer22A with 2 LEDs at output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VIPer22A with 8 LEDs at output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 VIPer12A EMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VIPer22A EMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 VIPer12A current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 VIPer22A current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Ripple at 264Vac (VIPer12A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Ripple at 264Vac (VIPer22A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Top Side of Board (not in scale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Bottom Side of Board (not in scale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Top board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Bottom board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 VIPer22A round LED EMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 VIPer12A round LED EMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 VIPer22A round LED board current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 VIPer12A round LED board current regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Ripple Current at 264Vac input (VIPer22A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Ripple Current at 264Vac input (VIPer12A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Non-isolated buck configuration schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 VIPer22A buck board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 AN1916 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Electrical characteristics at 350mA, junction temperature, TJ = 25 °C . . . . . . . . . . . . . . . . . 6 Flux characteristics at 350mA, junction temperature, TJ = 25 °C. . . . . . . . . . . . . . . . . . . . . 7 1 to 4 LEDs system at 350mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 to 8 LEDs system at 350mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 VIPer12A LED system at 700mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 VIPer12A LED system at 1.05A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 VIPer22A LED system at 700mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 VIPer22A LED system at 1.05A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Number of LEDs that can be driven . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 BOM change for VIPer22A 350mA solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Bill of matarials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Bill of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 5/45 LED parameters 1 AN1916 LED parameters LED voltage drop tolerance varies by +/- 16.6% for the white LED, as shown in Table 1. Different colors will have different typical voltage drop. For this reason, it is recommended that the LEDs be connected in series rather than parallel. If the LEDs were connected in parallel, the current flowing in each LED would depend on each unit's individual voltage drop (VF) characteristic and not be matched to the other devices, resulting in different brightness for each LED. Below is the forward voltage drop spec from the Luxeon Star Technical Data Sheet DS23 Table 1. Electrical characteristics at 350mA, junction temperature, TJ = 25 °C Forward Voltage VF(V) Color Min 6/45 Typ. Max Dynamic Resistance (Ω)RD Temperature Coefficient of Forward Voltage (mV/°C) ∆VF/∆TJ White 2.79 3.42 3.99 1.0 -2.0 Green 2.79 3.42 3.99 1.0 -2.0 Cyan 2.79 3.42 3.99 1.0 -2.0 Blue 2.79 3.42 3.99 1.0 -2.0 Royal Blue 2.79 3.42 3.99 1.0 -2.0 Red 2.31 2.85 3.27 2.4 -2.0 Amber 2.31 2.85 3.27 2.4 -2.0 AN1916 2 LED Intensity LED Intensity The intensity of the brightness also varies with different color as shown in the Luxeon data sheet. Table 2. Flux characteristics at 350mA, junction temperature, TJ = 25 °C Color Minimum Luminous Flux (lm) or Radiometric Power (MW) φV Typical Luminous Flux (lm) Or Radiometric Power (MW) φV White 13.9 25 Green 13.9 30 Cyan 13.9 30 Blue 3.8 10 Royal Blue 55MW 150MW Red 13.9 27 Amber 10.7 25 The brightness is directly related to the current driving the LED. A test was conducted in a closed box with a white LED mounted 12 inches away from the light meter. The results showed a linear relationship between current and light output as shown in Figure 1. Figure 1. also shows the relation between current and forward drop of the LED. 7/45 Design consideration 3 AN1916 Design consideration The main consideration in designing this constant current power supply is the transformer. Since one to four LEDs can be operated, and each LED is 3.5V nominal, the output can vary from 3.5V to 14V. The output voltage will be reflected back across the transformer and will in turn change the Vdd voltage to the control circuit and the peak Vds voltage across the MOSFET. The transformer must be designed with three limiting factors in mind. ■ Vdd, which has a range of 9V for under voltage to 38V for the over voltage threshold. ■ Wattage, specified at 8W for the VIPer12A and 12W for the VIPer22A ■ Reflected voltage across the drain of the MOSFET which is the turn ratio of (Np ÷ Ns) x Vout, added to the input voltage and must be below 730V. Figure 1. Current vs. LUX and VF In order to keep the reflected voltage manageable, the transformer is designed for a turn's ratio of primary to secondary output voltage for the maximum number of LEDs. Using this criteria, as the number of LEDs is reduced, so is the reflected voltage. If the transformer were based on one LED then the reflected voltage would quadruple with four LEDs and may exceed the rating of the VIPer. The turn's ratio between secondary to the Vdd winding is set for an output voltage of one LED to the minimum Vdd voltage, of 9V. As more LEDs are added, the Vdd voltage increases proportionally until it reaches the overvoltage shutdown point of 42V nominal. With this starting point a table can be derived as shown in Table 3. for the VIPer12 and Table 4. for VIPer22A. The highlighted values indicate parameters that are approaching the limit for that parameter. The following table shows the results of the parameters that should be considered for the proper design. 8/45 AN1916 Design consideration Table 3. # of LEDs 1 1 to 4 LEDs system at 350mA Output voltage at 350mA [1] Vdd Output Wattage Vds not V reflected including spike at 375Vdc Turns ratio Ns/Np 1 3.57 10.05 1.25 30.51282 405.5128 0.117 2 6.99 18.33 2.45 59.74359 434.7436 Nvdd/Ns 3 10.41 26.60 3.64 88.97436 463.9744 2.419 4 13.83 34.87 4.85 118.2051 493.2051 5 17.25 43.15 6.04 147.4359 522.4359 The output voltage includes 0.175V drop in the current sense resistor. In the case of Table 3., the Vdd would be the limiting factor reaching the over voltage shut down point. In the case of Table 4., the Vdd would be the limiting factor reaching the overvoltage shutdown point. The turn ratio of primary to secondary is based on the highest output voltage for 8 LEDs. The VIPer12A and VIPer22A are ideal for this application because of the wide range of Vdd. This ranges from 8 to 42V typical. The overvoltage kicks in at 42V, preventing the addition of LEDs driving the output voltage, the voltage across the drain to source and the wattage, from being exceeded. Table 4. 2 2 to 8 LEDs system at 350mA Output voltage at 350mA [2] 2 6.99 10.63 2.45 33.12796 408.128 0.211 3 10.41 15.67 3.64 49.33649 424.3365 Nvdd/Ns 4 13.83 20.71 4.84 65.54502 440.545 1.474 5 17.25 25.75 6.04 81.75355 456.7536 6 20.67 30.79 7.23 97.96209 472.9621 7 24.09 35.84 8.43 114.1706 489.1706 8 27.51 40.88 9.63 130.3791 505.3791 9 30.93 45.92 10.83 146.5877 521.5877 Vdd Output Wattage Vds not V reflected including spike at 375Vdc # of LEDs Turns ratio The output voltage includes 0.175V drop in the current sense resistor. The circuit shown in Figure 5. can drive from 1 to 4 LEDs. The circuit shown in Figure 6. can drive from 2 to 8 LEDs. Table 3. and Table 4. are based on the nominal voltage drop for a white LED as stated in the LED datasheet shown earlier. The actual number of LEDs that can be driven depends on the VF spread of the type of LEDs used and the Vdd range (9V to 38V) when worse case conditions are taken into account. Worse case parameters must be considered for a robust design. If the design calls for a fixed number of LEDs, then the only limiting factor is the VIPer's maximum output power capability. Table 5. to Table 8. will show the same measurements taken with 700mA and 1.05A at the output for VIPer12A and VIPer22A circuit configurations. Here, the limiting factor is the maximum output power that can be attained from VIPer12A and VIPer22A with 6W maximum and 10W maximum output power respectively. 9/45 Design consideration Table 5. AN1916 VIPer12A LED system at 700mA Output # of LEDs voltage at 700mA Output Wattage V reflected Vds not including spike at 375Vdc 1 3.67 13.22 2.61 30.51282 433 2 7.15 23.42 5.10 59.74359 464 Table 6. 1 Table 7. 3.42 Vdd 13.49 Output Wattage 3.49 V reflected 30.51282 Vds not including spike at 375Vdc 430 Output voltage at 700mA 2 7.18 11.75 5.026 33.12796 433 3 10.48 16.72 7.336 49.33649 447 4 13.48 21.2 9.436 65.54502 461 0.117 Turns ratio Ns/Np 0.117 Vdd Output Wattage V reflected Vds not including spike at 375Vdc Turns ratio 0.211 VIPer22A LED system at 1.05A Output # of LEDs voltage at 1050mA 2 Ns/Np VIPer22A LED system at 700mA # of LEDs Table 8. Turns ratio VIPer12A LED system at 1.05A Output # of LEDs voltage at 1050mA 10/45 Vdd 6.62 Vdd 11.5 Output Wattage 6.951 V reflected 33.12796 Vds not including spike at 375Vdc 433 Turns ratio 0.211 AN1916 4 Board description Board description This demonstration board is a redesign of earlier versions of the VIPer12A and VIPer22A LED driver reference designs. The board has been configured to allow the user to select the output current of 350mA, 700mA or 1.05A by using the jumpers, J2 and J4, on the board without having to change any components on the evaluation board. Table 9. below outlines the range of LEDs that can be driven depending on the version of board and type of LEDs selected: Table 9. Number of LEDs that can be driven Board Version 1W LED (Iout =350mA) 3W LED (Iout = 700mA) 5W LED (Iout = 1.05A) VIPer12A Min 1 Max 4 Min 1 Max 2 Min 1 Max 1 VIPer22A Min 2 Max 8 Min 2 Max 4 Min 2 Max 2 On the evaluation board, the value of the sense resistor is selected by jumpers J2 and J3. When both J2 and J3 are open, the sense resistor is set to 0.5Ω making the output current 0.35mA. When either J2 or J3 is shorted, the output sense resistor is fixed to 0.25Ω making the output current 700mA. With both J2 and J3 shorted, the output current will be set to 1.05A. 11/45 Transformer specifications 5 AN1916 Transformer specifications The transformer is designed and manufactured by Cramer Coil and Transformer Co. The electrical characteristics of the transformer are as follows: ● Primary Inductance: 3.25mH +/-10% ● Primary Leakage Inductance: 39.9µH typical ● HIPOT (N1, N3, N4 to N2): 4000VAC, 1Sec ● Turns Ratio (N1/N4:N2): 1:0.117 ● Turns Ratio (N1/N4:N3): 1:0.283 When the VIPerx2A (U4) is on, energy is stored in the primary winding of transformer (8-10), T1. This energy is transferred to the auxiliary winding (5-6), and to the output (1-2) when the VIPerx2A turns off. The auxiliary winding provides the bias voltage for the VIPerx2A at pin 4 (Vdd). Figure 2. Mechanical characteristics of the transformer An alternate source for the transformer is Midcom, Inc. The part number for the transformer on the VIPer12A LED and VIPer22A LED board are 31929 and 31928 respectively. Further information and samples could be obtained from http://www.midcom-inc.com. 12/45 AN1916 Current selectable reference board The evaluation board is designed to display the full functionality of VIPer12A and VIPer22A as LED drivers to drive 1W, 3W as well as 5W LEDs at wide range input voltage. The components selected are optimized for 5W LED driver application. The following pages contain the schematics and bills of materials that reflect the components used on the boards. Based on this circuit, there are six different configurations with different output power level that could be derived by making minor components changes to the evaluation board. The subsequent pages will show the schematics and bills of materials for the circuit to drive 1W, 3W and 5W LEDs. R10 1K VIPer12A current selectable LED driver schematic R5 750 R7 10K 5 Ve2+ Gnd 4 Vref Ve1- 3 2 Out1 C6 0.33uF 50V R15 24K R16 2.2K U3 6.2k 5% 1/4W R3 0 + 0 C4 22uF 50V 6 10 8 5 1 6 8 5 10 W1 2 4.7nF C5 2 2 D3 4 3 Cram er CVP11-047 1 1 1 2 STTH152 R4 100 5% 1/4W + 1 TSM103 7 6 Ve2- Out2 8 Vcc 1/2W 2 0.5 1/2W R9 2.2K 1 U2 2 R14 1 C7 220uF 25V 1 R12 0.5 1/2W 2 0.5 1/2W R13 1 J3 Jumper LED 1 2 3 4 5 6 2 2 1 2 1 LED + 2 J4 535676-5 1 J2 Jumper R11 1K C8 0.1uF 2 C10 VIPer12A 3 Source Tovl Fb 1 2 Drain DrainVdd Drain Drain U4 4 D2 STTH102 8 7 6 5 3 C1 4.7uF 400V D1 600V,1A DF06MGI + 4 1 Compostar45mH L1 2 1 . . + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W 2 R2 1 1 R8 10 1/4W 5% 2 4 J1 2 1 C11 0.047uF 6.8 5% 1/4W 1W FUSE F1 R1 2 3 Figure 3. 1 6 Current selectable reference board 13/45 Current selectable reference board Table 10. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Mounting 1 C1 4.7uF 400V Electrolytic TKR2GM4R7D Compostar Radial TH 1 C2 10uF 400V Electrolytic TKR2GM100D Compostar Radial TH 1 C3 47pF 1kV Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 25V Electrolytic EEU-FC1E221 Panasonic 1 C8 1 TH Radial TH Radial TH 0.1uF 50V Ceramic 1206 SMD C10 22Ga solid bus wire Axial TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic Radial TH 1 D1 DIPBridge 600V 1A DB105 Micro Commercial 1 D2 STTH102 diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH152 diode STTH152 STMicroelectronics Axial DO-15 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman Radial 1 J1 Phoenix 2 Pin Connector MKDSN1.5/2 Phoenix Contact TH 2 J2, J3 Current Select Jumper 22-28-8020 Molex TH 1 J4 Stackable Receptacle 535676-5 Tyco 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar 1 R1 6.8Ω 5% 1/4W Carbon Composition 1 R2 1 TH 6 Pin TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2Ω 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W 1206 SMD 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 10Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 1 R10 1kΩ 5% 0.25W Axial TH 1 R11 1kΩ 5% 0.25W 1206 SMD 3 R12, R13, R14 0.5Ω 5% 0.5W Axial TH 1 R15 24kΩ 5% 0.25W 1206 SMD 1 R16 2.2kΩ 5% 0.25W 1206 SMD 1 T1 Cramer Transformer 14/45 CVP11-047 Cramer Coil TH J1 2 1 C11 0.047uF 6.8 5% 1W 2 C1 10uF D1 400V DF06MGI 600V, 1A 1 + . L1 Compostar45mH 4 4 3 R1 5Ohms 3 2 1 FUSE + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 C10 C12 N.U 1 2 8 7 6 5 VIPer22A Source Tovl Fb Drain DrainVdd Drain Drain U4 3 4 D2 STTH102 R8 51 1/4W 5% 1 2 1 2 . F1 2 1 0 + C4 22uF 50V 0 6 8 5 1 D4 PKC-136 10 6 8 5 6.2k 5% 1/4W R3 W1 2 2 C6 0.33uF 50V 4.7nF C5 2 Cram er CVP11-046 1 1 10 D3 R4 100 5% 1/4W + R15 U3 24k 1/4W STTH152 R16 2.2k 1/4W 4 3 4 3 2 1 R13 1 Ve2+ Ve2- Out2 5 6 7 8 J3 Jumper J2 Jumper LED - R5 750 C8 0.1uF R11 1K 1/4W % R10 1K Mfg R7 10K 2 Vcc 2.2K 1/2W TSM103 Gnd Vref Ve1- 2 2 R9 0.5 1/2W R14 0.5 1/2W Out1 U2 1 1 C7 220uF 1 R12 2 50V 0.5 1/2W LED + J4 535676-5 Figure 4. 1 1 8 Pin DIP TH Dual OpAmp & Voltage TSM103ID Ref. STMicroelectronics SO8 SMD U4 Optocoupler Fairchild/LiteOn 4 Pin DIP TH W1 22 Ga solid bus wire Axial TH H11A817A/LTV817A 1 1 2 U3 2 1 STMicroelectronics VIPer12ADIP 1 VIPer12A 1 2 3 4 5 6 U2 2 1 1 Mfg P/N 2 Part Description 2 1 Qty Reference 2 Table 10. 1 AN1916 Current selectable reference board Bill of materials Geometry Mounting VIPer22A current selectable LED driver schematic 15/45 Current selectable reference board Table 11. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Radial Mounting 2 C1, C2 10uF 400V Electrolytic TKR2GM100D Compostar TH 1 C3 47pF 1kV Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FC1H221 Panasonic 1 C8 1 TH Radial TH Radial TH 0.1uF 50V Ceramic 1206 SMD C10 22Ga solid bus wire Axial TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic Radial TH 1 D1 DIPBridge 600V 1A DB105 Micro Commercial 1 D2 STTH102 diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH152 diode STTH152 STMicroelectronics Axial DO-15 TH 1 D4 Peak Clamp PKC136 STMicroelectronics Axial DO-15 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 1 J1 Phoenix 2 Pin Connector MKDSN1.5/2 Phoenix Contact TH 2 J2, J3 Current Select Jumper 22-28-8020 Molex TH 1 J4 Stackable Receptacle 535676-5 Tyco 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar 1 R1 5Ω 5% 1W wire wound Axial TH 1 R2 100Ω 5% 0.5W Axial TH 1 R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W 1206 SMD 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 51Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 1 R10 1kΩ 5% 0.25W Axial TH 1 R11 1kΩ 5% 0.25W 1206 SMD 3 R12, R13, R14 0.5Ω 5% 0.5W Axial TH 1 R15 24kΩ 5% 0.25W 1206 SMD 1 R16 2.2kΩ 5% 0.25W 1206 SMD 1 T1 Cramer Transformer CVP11-046 Cramer Coil TH 1 U2 VIPer22A VIPer22ADIP STMicroelectronics 8 Pin DIP TH 16/45 TH Radial 6 Pin TH TH TH 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 4.7uF 400V 1 + L1 Compostar45mH . 3 4 J1 6.8 5% 1/4W 1W 2 1 4 3 FUSE + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 Fb Vdd 3 4 0 + C4 22uF 50V 0 6 1 51T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 21T 1 Cram er CVP11-047 10 180T 10 R4 100 5% 1/4W R16 2.2K 1/4W R15 24K 1/4W + 4 3 2 1 C7 220uF 25V U2 Ve2- 8 5 6 7 R5 750 C8 0.1uF R11 1K R10 1K 1/4W Mfg R7 10K Vcc Out2 1 2 J2 R6 0.5 1/2W 2.2K 1/2W Ve2+ TSM103 Gnd Vref Ve1- Out1 R9 0.35A (3.5V - 14V) U3 H11A817A STTH102 D3 Mfg P/N VIPer12A Source Source Drain Drain Drain Drain U4 STTH102 D2 R8 10 1/4W 5% 1 2 R1 4 . F1 1 3 Part Description 2 1 Figure 5. 2 Qty Reference 2 Table 11. 1 AN1916 Current selectable reference board Bill of materials Geometry Mounting 1 U3 Dual OpAmp & Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U4 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 4 Pin DIP TH 1 W1 22 Ga solid bus wire Axial TH VIPer12A constant current (350mA) LED driver schematic 17/45 Current selectable reference board Table 12. AN1916 Bill of material Qty Reference Part Description Mfg P/N Mfg Geometry Mounting 1 C1 4.7uF 400V Electrolytic TKR2GM4R7D Compostar Radial TH 1 C2 10uF 400V Electrolytic TKR2GM100D Compostar Radial TH 1 C3 47pF 1kV Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 25V Electrolytic EEU-FC1E221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial 1 D2 STTH102 Diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH102 Diode STTH102 STMicroelectronics Axial DO-41 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 2 J1, J2 Phoenix 2 PIN Connector MKDSN1.5/2 Phoenix Contact TH 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar TH 1 R1 6.8Ω 5% 1/4W Carbon Composition 1 R2 1 TH Radial Radial Radial Radial TH TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W Axial TH 1 R6 0.5Ω 5% 0.5W Axial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 10Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 2 R10, R11 1kΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 1 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer CVP11-047 Cramer Coil TH 1 U2 Dual OpAmp&Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 1 U4 VIPer12A VIPer12A DIP 1 W1 22 Ga Solid Bus Wire 18/45 4 Pin DIP TH STMicroelectronics 8 PIN DIP TH TH 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 10uF 400V 1 + 3 2 1 4 L1 Compostar45mH . + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 Fb Vdd 3 4 STTH102 D2 R8 51 1/4W 5% 0 + D4 PKC-136 VIPer22A Source Source Drain Drain Drain Drain U4 1 2 J1 6.8 5% 1W 5Ohms 1 2 4 3 FUSE C4 22uF 50V 0 6 1 56T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 38T 1 Cram er CVP11-046 10 180T 10 R4 100 5% 1/4W STTH102 D3 R16 2.2k R15 24k 4 3 R1 1 2 4 3 2 1 1/2W R9 2.2K 1 R7 10K Ve2- Out2 Vcc 2 Ve2+ TSM103 Gnd Vref Ve1- Out1 U2 C7 220uF 50V U3 H11A817A + 0.35A (7V - 27.5V) 1 2 . F1 5 6 7 8 R6 0.5 1/2W 1 2 J2 R5 750 2 C8 0.1uF R11 1K R10 1K 1/4W Figure 6. 1 AN1916 Current selectable reference board VIPer22A constant current (350mA) LED driver schematic 19/45 Current selectable reference board Table 13. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Radial Mounting 2 C1, C2 10uF 400V Electrolytic TKR2GM100D Compostar TH 1 C3 47pF 1Kv Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FC1H221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial TH 2 D2, D3 STTH102 diode STTH102 STMicroelectronics Axial DO-41 TH 1 D4 Peak Clamp PKC136 STMicroelectronics Axial DO-15 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 2 J1, J2 Phoenix 2 Pin Conn MKDSN1.5/2 Phoenix Contact TH 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar TH 1 R1 5Ω 5% 1W Wirewound 1 R2 1 TH Radial Radial Radial TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W Axial TH 1 R6 0.5Ω 5% 0.5W Axial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 51Ω 5% 0.25W Axial TH 1 R9 2.2k 5% 0.5W Axial TH 2 R10, R11 1KΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 1 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer CVP11-046 Compostar TH 1 U2 Dual OpAmp & Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 1 U4 VIPer22A VIPer22ADIP 1 W1 22 Ga solid bus wire 3 20/45 4 Pin DIP TH STMicroelectronics 8 Pin DIP TH Axial TH The following components are changed for the VIPer22A constant current (350mA) LED driver configuration from the VIPer12A constant current (350mA) LED driver configuration. 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 4.7uF 400V 1 + L1 Compostar45mH . 3 4 J1 6.8 5% 1/4W 1W 2 1 4 3 R1 + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 U4 Fb Vdd VIPer12A Source Source Drain Drain Drain Drain 3 4 STTH102 D2 R8 10 1/4W 5% 1 2 FUSE 0 + C4 22uF 50V 0 6 1 51T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 21T 1 Cram er CVP11-047 10 180T 10 4 3 2 1 C7 220uF 25V U2 Ve2+ R7 10K Ve2- Out2 Vcc 2 LED - R9 1/2W 2.2K 1 LED + TSM103 Gnd Vref Ve1- Out1 0.7A 5 6 7 8 R6 0.25 1/2W 1 2 J2 R5 750 C8 0.1uF R11 1K R10 1K 1/4W Reference R16 2.2k 1/4W R15 24k 1/4W + U3 H11A817A R4 100 5% 1/4W STTH102 D3 4 3 . F1 1 2 1 Quantity 2 Figure 7. 2 Table 14. 1 AN1916 Current selectable reference board BOM change for VIPer22A 350mA solution Description 1 C1 10uF/400V electrolytic 1 C7 220uF/50V electrolytic 1 R8 51Ω 5% 0.25W 1 D4 STMicroelectronics PKC-136 1 T1 Cramer Coil transformer CVP11-046 1 U4 STMicroelectronics VIPer22A VIPer12A constant current (700mA) LED driver schematic 21/45 Current selectable reference board Table 15. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Mounting 1 C1 4.7uF 400V Electrolytic TKR2GM4R7D Compostar Radial TH 1 C2 10uF 400V Electrolytic TKR2GM100D Compostar Radial TH 1 C3 47pF 1kV Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FH1E221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial 1 D2 STTH102 Diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH102 Diode STTH102 STMicroelectronics Axial DO-41 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 2 J1, J2 Phoenix 2 PIN Connector MKDSN1.5/2 Phoenix Contact TH 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar TH 1 R1 6.8Ω 5% 1/4W Carbon Composition 1 R2 1 TH Radial Radial Radial Radial TH TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Radial TH 1 R5 750Ω 5% 0.25W Radial TH 1 R6 0.25Ω 5% 0.5W Radial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 10Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 2 R10, R11 1kΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 1 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer CVP11-047 Cramer Coil TH 1 U2 Dual OpAmp&Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 4 Pin DIP TH 1 U4 VIPer12A VIPer12A DIP STMicroelectronics 8 Pin DIP TH 1 W1 22 Ga Solid Bus Wire 22/45 TH 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 10uF 400V 1 + 3 4 L1 Compostar45mH . 2 1 J1 6.8 5% 1W 5Ohms + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 Fb Vdd 3 4 STTH102 D2 R8 51 1/4W 5% 0 + D4 PKC-136 VIPer22A Source Source Drain Drain Drain Drain U4 1 2 4 3 FUSE 1 2 R1 C4 22uF 50V 0 6 1 56T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 38T 1 Cram er CVP11-046 10 180T 10 R4 100 5% 1/4W STTH102 D3 R16 2.2k R15 24k 4 3 . F1 1 2 4 3 2 1 1/2W Ve2+ R7 10K Ve2- Out2 Vcc 2 LED- R9 2.2K 1 LED+ TSM103 Gnd Vref Ve1- Out1 U2 C7 220uF 50V U3 H11A817A + 0.7A 1 2 5 6 7 8 R6 0.25 1/2W 1 2 J2 R5 750 C8 0.1uF R11 1K R10 1K 1/4W Figure 8. 2 1 AN1916 Current selectable reference board VIPer22A constant current (700mA) LED driver schematic 23/45 Current selectable reference board Table 16. AN1916 Bill of matarials Qty Reference Part description Mfg P/N Mfg Geometry Radial Mounting 2 C1, C2 10uF 400V Electrolytic TKR2GM100D Compostar TH 1 C3 47pF 1Kv Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FC1H221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial TH 2 D2, D3 STTH102 diode STTH102 STMicroelectronics Axial DO-41 TH 1 D4 Peak Clamp PKC136 STMicroelectronics Axial DO-15 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 2 J1, J2 Phoenix 2 Pin Conn MKDSN1.5/2 Phoenix Contact TH 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar TH 1 R1 5Ω 5% 1W Wirewound 1 R2 1 TH Radial Radial Radial TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W Axial TH 1 R6 0.25Ω 5% 0.5W Axial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 51Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 1 R10, R11 1KΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 2 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer CVP11-046 Cramer Coil TH 1 U2 Dual OpAmp & Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 4 Pin DIP TH 1 U4 VIPer22A VIPer22ADIP STMicroelectronics 8 Pin DIP TH 1 W1 22 Ga solid bus wire 24/45 Axial TH 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 4.7uF 400V 1 + 3 4 L1 Compostar45mH . 2 1 J1 6.8 5% 1/4W 1W + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 Fb Vdd VIPer12A Source Source Drain Drain Drain Drain U4 3 4 STTH102 D2 R8 10 1/4W 5% 1 2 4 3 FUSE 0 + C4 22uF 50V 0 6 1 51T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 21T 1 Cram er CVP11-047 10 180T 10 R4 100 5% 1/4W R16 2.2k 1/4W R15 24k 1/4W + 4 3 2 1 U2 Ve2+ R7 10K Ve2- Out2 Vcc 2 LED - R9 1/2W 2.2K 1 LED + TSM103 Gnd Vref Ve1- Out1 1.05A C7 220uF 25V U3 H11A817A STTH152 D3 4 3 R1 1 2 1 2 . F1 5 6 7 8 R6 0.167 1/2W 1 2 J2 R5 750 2 C8 0.1uF R11 1K R10 1K 1/4W Figure 9. 1 AN1916 Current selectable reference board VIPer12A constant current (1.05A) LED driver schematic 25/45 Current selectable reference board Table 17. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Mounting 1 C1 4.7uF 400V Electrolytic TKR2GM4R7D Compostar Radial TH 1 C2 10uF 400V Electrolytic TKR2GM100D Compostar Radial TH 1 C3 47pF 1kV Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FH1E221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial 1 D2 STTH102 Diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH152 Diode STTH152 STMicroelectronics Axial DO-41 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman 2 J1, J2 Phoenix 2 PIN Connector MKDSN1.5/2 Phoenix Contact 1 L1 45mH common mode FUU10S-V24503-Q22650 Compostar choke 1 R1 6.8Ω 5% 1/4W 1 R2 1 Radial Radial Radial Radial TH TH TH TH TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W Axial TH 1 R6 0.167Ω 5% 0.5W Axial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 10Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 2 R10, R11 1kΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 1 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer 1 U2 Dual OpAmp&Voltage TSM103ID Ref. 26/45 Carbon Composition TH CVP11-047 Cramer Coil TH STMicroelectronics SO8 SMD 2 1 C11 0.047uF X cap 2 D1 600V,1A DF06MGI C1 10uF 400V 1 + 3 4 L1 Compostar45mH . 2 1 J1 6.8 5% 1W + C2 10uF 400V C3 47pF 1kV 0 100 5% 1/2W R2 1 2 8 7 6 5 Fb Vdd 3 4 STTH102 D2 R8 51 1/4W 5% 0 + D4 PKC-136 C4 22uF 50V 0 6 1 56T 8 5 6 8 5 6.2k 5% 1/4W R3 W1 2 1 2 C6 0.33uF 50V Y cap 4.7nF C5 2 38T 1 Cram er CVP11-046 10 180T 10 R4 100 5% 1/4W STTH152 D3 R16 2.2k R15 24k 4 3 2 1 1/2W Ve2+ 5 6 7 8 R6 0.167 1/2W 1 2 J2 R5 750 C8 0.1uF R11 1K R10 1K 1/4W Mfg R7 10K Ve2- Out2 Vcc 2 LED- R9 2.2K 1 LED+ TSM103 Gnd Vref Ve1- Out1 U2 C7 220uF 50V U3 H11A817A + 1.05A Mfg P/N VIPer22A Source Source Drain Drain Drain Drain U4 1 2 4 3 FUSE 1 2 1 R1 5Ohms 4 3 . F1 1 2 Part Description 2 Qty Reference 2 Table 17. 1 AN1916 Current selectable reference board Bill of materials Geometry Mounting 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 4 Pin DIP TH 1 U4 VIPer12A VIPer12A DIP STMicroelectronics 8 Pin DIP TH 1 W1 22 Ga Solid Bus Wire TH Figure 10. VIPer22A constant current (1.05A) LED driver schematic 27/45 Current selectable reference board Table 18. AN1916 Bill of materials Qty Reference Part Description Mfg P/N Mfg Geometry Mounting 2 C1, C2 10uF 400V Electrolytic TKR2GM100D Compostar 1 C3 47pF 1Kv Ceramic ECC-D3A470JGE Panasonic 1 C4 22uF 50V Electrolytic EEU-FC1H220 Panasonic 1 C5 4.7nF 250V Ceramic ECK-DNA472ME Panasonic TH 1 C6 0.33uF 50V Ceramic ECU-S1H334KBB Panasonic TH 1 C7 220uF 50V Electrolytic EEU-FC1H221 Panasonic 1 C8 0.1uF 50V Ceramic ECU-S1H104BB Panasonic TH 1 C11 0.047uF 250V boxcap ECQ-U2A473MG Panasonic TH 1 D1 DipBridge 600V 1A DB105 Micro Commercial TH 1 D2 STTH102 diode STTH102 STMicroelectronics Axial DO-41 TH 1 D3 STTH152 diode STTH152 STMicroelectronics Axial DO-41 TH 1 D4 Peak Clamp PKC136 STMicroelectronics Axial DO-15 TH 1 F1 Fuse TR5 0.5A 3720500041 Wickman TH 2 J1, J2 Phoenix 2 Pin Conn MKDSN1.5/2 Phoenix Contact TH 1 L1 45mH common mode choke FUU10S-V24503Q22650 Compostar TH 1 R1 5Ω 5% 1W Wirewound 1 R2 1 Radial TH TH Radial Radial Radial TH TH Axial TH 100Ω 5% 0.5W Axial TH R3 6.2kΩ 5% 0.25W Axial TH 1 R4 100Ω 5% 0.25W Axial TH 1 R5 750Ω 5% 0.25W Axial TH 1 R6 0.167Ω 5% 0.5W Axial TH 1 R7 10kΩ 5% 0.25W Axial TH 1 R8 51Ω 5% 0.25W Axial TH 1 R9 2.2kΩ 5% 0.5W Axial TH 2 R10, R11 1KΩ 5% 0.25W Axial TH 1 R15 24kΩ 5% 0.25W Axial TH 1 R16 2.2kΩ 5% 0.25W Axial TH 1 T1 Cramer Transformer CVP11-046 Cramer Coil TH 1 U2 Dual OpAmp & Voltage Ref. TSM103ID STMicroelectronics SO8 SMD 1 U3 Optocoupler H11A817A/LTV817A Fairchild/LiteOn 4 Pin DIP TH 1 U4 VIPer22A VIPer22ADIP STMicroelectronics 8 Pin DIP TH 1 W1 22 Ga solid bus wire 28/45 Axial TH AN1916 7 PCB layout PCB layout Figure 11. Board top side (not in scale) Figure 12. Board bottom side viewed from top side (not in scale) 29/45 General circuit description 8 AN1916 General circuit description The design operates from 90 to 264Vac input. The AC input is rectified and filtered by the bridge BR1 to generate the high voltage DC bus that is applied to the primary winding of the transformer, CVP11-04X. C1, L1, C2, and C11 provide EMI filtering for the circuit. A snubber circuit that consists of R2 and C3 reduces the leakage spike and voltage ringing on the drain pin of VIPerX2A, thereby provides additional EMI filtering. A transil, PKC-136, is used to clamp the drain voltage at a safe level for the VIPer22A constant current LED driver configuration because of the extra power level. The current is controlled by monitoring the voltage drop across the sense resistor, R6. The non-inverting input of the operational amplifier inside TSM103 is set to 175mV through the resistors divider, R5 and R7. This operational amplifier will then regulate the inverting input to 175mV by adjusting its output by changing the current going through the optocoupler, H11A817A (U3). The gain of the transistor inside the optocoupler then controls the feedback loop of VIPerX2A. The LED drive current is given by the equation: Iout=0.175V/R6 C6, C8, and R11 are utilized to ensure the stability of the circuit. C7 reduces the ripple current. As a safety measure, a resistor divider consisting of R15 and R16 is added to clamp the output voltage fed back into TSM103 so that it does not exceed the maximum voltage rating of U2, TSM103 for a no load condition at the output. 30/45 AN1916 9 Waveforms Waveforms Figure 13. shows VDD, Vout, and VDS at 375Vdc with one LED at the output for the VIPer12A constant current LED driver configuration while Figure 14. shows likewise with four LEDs at the output. Figure 13. VIPer12A with 1 LED at output Figure 14. VIPer12A with 4 LEDs at output The drain to source voltage, VDD, and Vout waveforms are shown in Figure 15. and Figure 16., taken at 375Vdc for two and eight LEDs at the output respectively. It can be seen at worse case condition, the voltages across the device are not exceeded. Figure 15. VIPer22A with 2 LEDs at output Figure 16. VIPer22A with 8 LEDs at output 31/45 EMI results 10 AN1916 EMI results Both VIPer12A and VIPer22A constant current LED driver configurations were designed to pass EN55022 Class B EMI at 120Vac input. Peak EMI is met with a comfortable margin. Figure 17. VIPer12A EMI 32/45 Figure 18. VIPer22A EMI AN1916 Current regulation The VIPer12A and the VIPer22A have excellent regulation as shown in Figure 19. and Figure 20. Figure 19. VIPer12A current regulation Output current 1 to 4 LEDs VSOutput current 400 390 380 370 360 350 340 330 320 310 300 1 2 3 4 LEDs Figure 20. VIPer22A current regulation 2 to 8 LEDs VS Output current 360 Output current 11 Current regulation 350 340 330 320 310 300 2 3 4 5 6 7 8 LEDs 33/45 Ripple current 12 AN1916 Ripple current The ripple current measured at 90Vac with one LED at the output is 59mVpp and it is 57mVpp at 264Vac input for the VIPer12A constant current LED driver configuration. With four LEDs at the output the measured ripple current is 46mVpp at 264Vac input. Figure 22. shows the ripple current measurements for the VIPer22A constant current LED driver configuration. Here, the measured ripple is 26mVpp at 264Vac input with 2 LEDs at the output while the ripple is 19.5mVpp for 8 LEDs at the output. Figure 21. Ripple at 264Vac (VIPer12A) 34/45 Figure 22. Ripple at 264Vac (VIPer22A) AN1916 13 1.8" Round LED board configuration 1.8" Round LED board configuration Another version is available of the rectangular VIPer12A LED driver and VIPer22A LED driver boards that fits inside a round 1.8" in diameter light fixture. The following sections will describe the layout and performance of this board. 35/45 Round LED board layout 14 Round LED board layout Figure 23. Top Side of Board (not in scale) Figure 25. Top board layout Figure 26. Bottom board layout 36/45 AN1916 Figure 24. Bottom Side of Board (not in scale) AN1916 15 EMI result EMI result The VIPer22A LED driver round board passes EN55022 Class B EMI at 120Vac input as shown in Figure 27. below. Figure 28. shows the EMI results at 120Vac input for VIPer12A round LED driver board. Figure 27. VIPer22A round LED EMI Figure 28. VIPer12A round LED EMI 37/45 Current regulation 16 AN1916 Current regulation The current regulation measured is ±0.15% at 120Vac input with 2 to 8 LEDs at the output for the VIPer22A round LED driver board. Figure 29. VIPer22A round LED board current regulation Iout (A) Current Regulation 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 Iout 1 3 5 7 9 #of LEDs Figure 30. VIPer12A round LED board current regulation Iout (A) Current Regulation 0.38 0.37 0.36 0.35 0.34 0.33 0.32 0.31 0.3 Iout 0 1 2 3 Number of LEDs 38/45 4 5 AN1916 17 Ripple current Ripple current Figure 31. below shows the ripple current measured with 2 LEDs and 8 LEDs at the output for 264Vac input for the VIPer22A round LED driver board. With 2 LEDs at the output, the measured ripple current is 51mApp while the ripple is 43mApp for 8 LEDs at the output. With 1 LED at the output for the VIPer12A round LED driver board, the measured ripple current is 65mApp and 45mApp for 4 LEDs at the output. Figure 31. Ripple Current at 264Vac input (VIPer22A) Figure 32. Ripple Current at 264Vac input (VIPer12A) 39/45 Low cost option 18 AN1916 Low cost option A lower cost alternative to the isolated VIPer12A power supply is to use the VIPer22A in a non-isolated Buck configuration as shown in Figure 33. The circuit uses fewer and less expensive parts for systems that do not require safety isolation. Figure 33. Non-isolated buck configuration schematic D6 1N400 5 D1 1N4007 Fusable res istor 90 TO 264 vAC L0 Source 3 SourceFb R0 10 1/2W D8 1 N4005 C3 1uF 25V 2 LED, R3=jumper 1 LED, R3= 1Ohms 2W Cx .022 50V L1 1 10V @ 320mA 1m H 1m H R1 1K C1 4.7uF 400V W1 C4 0.4 7 25V 1 2 U1 VIPer 2 2 8 7 6 5 C7 0.1u 250V Drain 4 Drain Vdd Drain Drain DZ 10V 1N5240 D5 STTA106 C2 4.7uF 400V C6 33uF 63V 2 R2 R3 10 2W 10 2W DZ1 16V 1n5246 0 C1, L0, and C2 form an EMI filter to meet emission standards. D6, C3 maintain voltage for Vdd. L1 and C6 form the output filter to average the DC output. The output is voltage regulated at 10V by the zener diode DZ1. R2 drops the voltage and sets the current to approximately 330mA. A different value resistor can be used to set the current to a value up to 370mA which is the limiting factor of L1, the output inductor. This unit will drive 2 LEDs or 1 LED by cutting one jumper before use. To drive 1 LED only, the jumper can be cut, placing a second resistor in series with the output to drop additional voltage. This is not as efficient as the previous design but simpler and less expensive. The output is set to 10V because that is the minimum output voltage that will drive the VIPer22A with these minimum parts. With the addition of an inductor, 2 of 1N4005 and a small capacitor, a lower voltage can be designed to increase the efficiency. Table 19. Bill of materials Quantity 40/45 Reference Description 1 Cx 0.022uF/50V 1206SM 2 C1, C2 4.7uF/400V electrolytic 1 C3 1uF/25V electrolytic 1 C4 0.47uF/25V 1206SM 1 C6 33uF/63V low ESR 1 C7 0.1uF/630V poly 1 DZ 1N5240 (10V) AN1916 Low cost option Table 19. Bill of materials Quantity Reference Description 1 DZ1 1N5246 (16V) 1 D1 1N4007 1 D5 STMicroelectronics STTA106 2 D6, D8 1N4005 1 L0 1mH 160mA JW Miller 5300-37 1 L1 1mH 400mA Compostar Q3277 1 R0 10Ω 1/2W fusable resistor 1 R1 1kΩ 1/4W 2 R2, R3 10Ω 2W 1 U1 STMicroelectronics VIPer22A 1 W1 Jumper wire 41/45 PCB layout 19 AN1916 PCB layout Below is a reference design of the VIPer22A-Buck LED driver above. The board measures 67mm x 26mm. Figure 34. VIPer22A buck board layout 42/45 AN1916 20 Conclusion Conclusion We have shown two isolated and one non-isolated off line power supplies to efficiently drive LEDs in series. 43/45 Revision history 21 AN1916 Revision history Table 20. 44/45 Document revision history Date Revision Changes 10-Sep-2004 1 Initial release 18-Jan-2006 2 Various changes 03-May-2006 3 - New template - Various changes 10-Aug-2006 4 - New template - Component list value modified - Schematic diagram modified AN1916 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. 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