LED-DRIVER-TEST 25W Mega-Zenigata LED Purpose To check compatibility of Sharp 25W Mega‐Zenigata LEDs with Recom AC/DC LED Drivers, a sample of 3pcs GW5DLC40M04 LEDs were tested with a sample of 3pcs RACD30‐700 and 3pcs RACD20‐500 to generate a matrix result. Conclusions The RACD30‐700 is fully compatible with the 25W Mega‐Zenigata LED run at full power (25W). The RACD20‐500 is fully compatible with the 25W Mega‐Zenigata LED run at reduced power (20W). Test Setup 25W Mega‐Menigata LED RACD30‐700 RACD20‐500 Test Equipment Output Voltage Meter: Output Current Meter: Input Voltage: Ambient temperature: LED: LED‐Driver: Recom Testbed Recom Testbed 230V AC 27.5°C 3x Sharp Mega‐Zenigata 25W mounted on a heatsink 3x RACD30‐700 3xRACD20‐500 1-3 LED-DRIVER-TEST Results Results were measured after a short 10‐15 seconds stabilisation time to reduce the effects of LED self‐heating. LED Driver LED 1 LED 2 LED 3 RACD30‐700 (Datecode 1044) RACD30‐700 (Datecode 1118) RACD30‐700 (Datecode 1118) 38.8V @ 666mA 38.9V @ 668mA 38.9V @ 668mA 38.7V @ 667mA 38.8V @ 669mA 38.7V @ 667mA 38.9V @ 667mA 39.0V @ 669mA 38.9V @ 667mA RACD20‐500 (Datecode 1044) RACD20‐500 (Datecode 1044) RACD20‐500 (Datecode 1044) 37.7V @ 488mA 37.7V @ 485mA 37.7V @ 482mA 37.6V @ 488mA 37.6V @ 485mA 37.6V @ 482mA 37.8V @ 488mA 37.7V @ 485mA 37.7V @ 482mA RACD30‐700 Average current 667.5mA Average voltage 38.8V LED Driver specification 700mA +/‐10% LED Driver specification 43V max. 95.4% nominal Average measured voltage 90% max. Average current 485mA Average voltage 37.7V LED Driver specification 500mA +/‐10% LED Driver specification 40V max. Average measured current RACD20‐500 Average measured current 97% nominal Average measured voltage 94% max. LED 2 was tested with a constant voltage supply to check its characteristic: GW5DLC40M04 Vf 30 If [mA] datasheet 0 If [mA] measured 0 31 20 5 32 33 50 110 20 50 34 220 103 35 350 171 36 500 266 37 700 380 38 ‐ 510 39 ‐ 650 40 ‐ 800 Measured Results Datasheet (Source: SHARP Application Notes) LED Current 900 800 700 600 500 400 300 200 100 0 30 31 32 33 34 35 36 37 38 39 40 2-3 LED-DRIVER-TEST Interpretation of Results 1. The Mega‐Zenigata datasheet specifies a typical forward voltage of 37V @ 700mA and 25°C, with a maximum of 41V. The average measured value for 3 samples was 38.8V @ 667.7mA. 2. Both the actual measured forward voltage and the datasheet maximum Vf lie within the output voltage range of the RACD30‐700 LED driver. 3. The output current of the RACD30‐700 drivers were within specification. 4. The Mega‐Zenigata datasheet specifies a typical forward voltage of 36V @ 500mA and 25°C. The average measured value for 3 samples was 38.8V @ 485mA. 5. Both the actual measured forward voltage and the datasheet typical Vf lie within the output voltage range of the RACD20‐500 LED driver. 6. The output current of the RACD20‐500 drivers were within specification. 7. The measured Forward Voltage vs. Current graph of the Mega‐Zenigata disagreed with the datasheet data, but followed the same shape. The difference was not important to the operation of the LED drivers (they are constant current devices which automatically adjust their output voltage to compensate for variations in LED characteristics). Steve Roberts Recom Technical Manager 29.06.2011 3-3