AC vs DC LED Design/Benefits JD(Doug) Rooks Western Area Applications Manager Seoul Semiconductor
Product Summary Acriche Side View LED Dot Matrix Z-Power LED Chip LED Lamp LED Custom Display Deep UV Top View LED High Flux LED Near UV
Creating DC Power From AC Alternating Current or AC is a voltage that varies over time as it is delivered by the power company To be used you need to convert the AC into DC using a bridge rectifier (turning AC into pulsed DC) and then filtering (smoothing the pulsed DC into a continuous DC)
Rectification 340 Vp p (x.707 = 240Vrms) Diode Bridge 170Vp p (x.707 = 120Vrms) 1. Believe it or not, what comes out of the wall of the typical 120V US plug is actually ~340V peak to peak. 2. The 120VAC actually refers to the voltage from the 0 line to either the positive or negative peak, multiplied by 0.707. 3. To reduce the rectified voltage to a usable level, a transformer is used to step it down
Filtering Passive components are used to smooth the rectified signal to a constant DC voltage Without control, the output voltage will fluctuate with input voltage
Switchers and Controllers The basic building blocks are as follows:
Component Selection Inductor- very robust essentially a coil of wire wrapped around a piece of iron Height issue Controller- this is a semiconductor chip and is usually constructed to handle high temperatures Capacitor- this is usually the component of interest. If properly selected then it can handle harsh environments and heat. This means a more expensive component must be selected Height issue
Creating a Solid State Light AC and DC solid state lights have common design criteria: Amount of Power: Total electrical power helps control the potential replacement value System efficacy ensures certifications Amount of Light: Total luminance determines the number of required LEDs Total illuminance takes advantage of the directionality of LEDs Thermal Considerations: Cannot be ignored though it may be new to some designers Establishes the life of the system System Cost Artistry
DC LED Luminaire The DC solid state light requires conversion from AC to DC power and focuses on: Efficiency consideration A 15% power loss in the conversion from AC to DC is typical, but may be greater if done improperly Sub-components lifetimes Must be carefully selected to ensure long life Sub-components size Sub-system placement Especially important tto not tblock kthe thermal path thfor dissipating i heat
AC LED Luminaire The AC solid state light does not need a complex AC to DC power supply Direct connection to AC, or through a simple resistor circuit Few or no sub-component lifetime or size implications New AC LEDs rival DC LED efficacy Easier to get UL with UL Recognized LED But there are new concerns Must design to not expose AC wiring or connectors Power Factor Total Harmonic Distortion *Courtesy of NGL-Supply
Introducing Acriche Direct AC-driven LED without AC-DC converter Radiant chip Operating high voltage - put dozens of lighting cells on one die LED
Acriche Operation
Comparing with DC LED Acriche Acriche. Acriche is only component DC - LED. Requires two key components Components AC power source AC power source AC/DC Converter Cost No added driver cost. Cost of components such as driver, assembly and design Lifetime. 35,000 hrs of lifetime not reduced by driver. Lifetime limited by driver. Shorter lifetime. More reliable solution under heat and challenging condition Efficiency. No conversion loss. AC/DC converter losses up to 30% Converter Others. Additional space needed for converter. Fire hazard and low reliability caused by heat emission and converter
Acriche Series A3 Advantages & Benefits. AC driven without converter or driver - Simplify circuit design - No conversion loss - Cost down - Reduce weight - No lifespan reduction by secondary components. Dimming available Applications. Indoor lighting. Bulb replacement. Down Light. Outdoor lighting Electrical Optical Characteristics Part No. VF IF Øv Color Temp. CRI Viewing Angle Absolute Thermal Maximum Ratings Thermal Resistance [TJ, ] [V] [ma] [lm] [K] [º] [RθJ-C, ºC /W] AN3200 100, 110 40 AN3220 220, 230 20 AW3200 100, 110 40 AW3220 220, 230 20 155 3000 80 230 6300 75 130 125 6
Acriche Series A4 Advantages & Benefits. AC driven without converter or driver - High voltage operation (AC50~55V) 55V) - High efficiency Acriche - Reduce weight - ESD protection (>4KV,HBM) - Life time (40khr@Junction temp=85 ) Applications Size : 7 x 7 x 2.95. Indoor lighting. Bulb replacement. Down Light. Ceiling panel light. Outdoor lighting Electrical Optical Characteristics Part No. Operating condition Power dissipation Øv Efficiency Color Temp. CRI Viewing Angle Thermal Resistance [ma, RMS@55V] [W] [lm] [lm/w] [K] [º] [RθJ-C, ºC /W] AN4240 AW4240 20 0.83 0.80 60 80 72 100 3000 6000 85 134 10 Schedule for Improved A4 Mass production Initial Sample Reliability sample Mass production June June July
A3 vs A4 Architecture A3 A4 R Concept AC source Acriche AC source Bridge didoe R New Acriche Products < A2 series > < A3 series > < A4 series > Characteristics - Bi direction Acriche - Only R is the exterior component - 100 ~ 230V operating for one PKG - Efficiency : warm white : 45lm/W (Typ.) - One direction Acriche (High voltage DC LED) - Bridge diode, R - 50 ~ 55V operating for one PKG - Efficiency : warm white 65lm/W (Typ.)
Acriche Series A5 Advantages & Benefits. AC driven without converter or driver -High voltage operation (AC110 / 220V) - 2W Product - Expected life time (40khr@Junction temp=85 ) Applications Size : 7 x 7 x 2.95 mm Mass Production : July, 2010. Indoor lighting. Bulb replacement. Candle lamp. Outdoor lighting Electrical Optical Characteristics Part No. Operating condition Power dissipation Øv Efficiency Color Temp. CRI Viewing Angle Thermal Resistance [ma, RMS] [W] [lm] [lm/w] [K] [º] [RθJ-C, ºC /W] AW52X0 AN52X0 20 @110V, 10@220V 1.67 90 70 54 42 6300 3000 70 80 140 11 Schedule for A5 Mass production Initial Sample Reliability sample Mass production - May End of June
Acriche Series A6 Advantages & Benefits. AC driven without converter or driver - High voltage operation (AC50~55V) - Compact size - Reduce weight - ESD protection (>4KV,HBM) - Expected life time (40khr@Junction temp=85 ) Applications Size : 5 x 5 x 2.6 mm Mass Production : August, 2010. Indoor lighting g. Ceiling gpanel light. Bulb replacement. Outdoor lighting. MR16. PAR. Down Light Electrical Optical Characteristics Operating Power Color Viewing Thermal Øv Efficiency CRI Part No. condition dissipation Temp. Angle Resistance [ma, RMS@55V] [W] [lm] [lm/w] [K] [º] [RθJ-C, ºC /W] A6 20 0.83 83 55 100 66 6300 70 120 12 Schedule for Improved da6 Mass production Initial Sample Reliability sample Mass production June June End of August
Acriche Series A7 Advantages & Benefits. AC driven without converter or driver - High voltage operation (AC110V, 220V) - Compact size - Reduce weight - ESD protection (>4KV,HBM) - Expected life time (40khr@Junction temp=85 ) Size : 8 x 8 x 2.9 mm Mass Production : August, 2010 Applications. Indoor lighting. Bulb replacement. MR16. PAR. Down Light. Ceiling panel light. Outdoor lighting Electrical Optical Characteristics Part No. Operating condition Power dissipation Øv Efficiency Color Temp. CRI Viewing Angle Thermal Resistance [ma, RMS@220V] [W] [lm] [lm/w] [K] [º] [RθJ-C, ºC /W] A7 Cool A7 Warm 20 3.2 290 185 90 58 6300 3000 70 80 120 7~8 A7 Schedule Initial Sample Reliability sample Mass production June June End of August
Pros and Cons Of DC LEDs DC Pros -Lumen per watt number -Many sources and suppliers to choose from -Many existing optic solutions for common packages DC Cons -Power conversion can add substantial cost -Use of high reliability components is imperative -Designs can be complex -Many leading semiconductor companies are involved in creating solutions -Switching power supplies can radiate electrical interference -Can create a thermal barrier between the LED and the ambient path
Pros and Cons Of AC LEDs Pros -Ease of implementation Cons -Fairly new so optics still emerging -Fewer components -Care of isolating exposed AC -System can be less expensive -Few suppliers -LED determines system lifetime -Need simple THD circuit -No power supply to clog thermal path
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