LED test / review - OSRAM OSLON Black Flat HWQP - still highest luminance of all LEDs to date!

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koef3's picture
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LED test / review - OSRAM OSLON Black Flat HWQP - still highest luminance of all LEDs to date!

LED test / review




Osram Oslon Black Flat HWQP


LUW HWQP-8M7N-ebvF46fcbB4



Since several months this LED is a well-known and popular choice for ultra-long range distance flashlights (throwers). Many performance values are already known from other users / tests, but with this test / review I want give you and all these who want to start a project with this very interesting LED the opportunity to check all values and important informations in one single post.




Technical data



Tj 25 °C / If 1,000 mA unless noted otherwise


Order code: LUW HWQP-8M7N-ebvF46fcbB4

Type: single die (lateral)
Binning: 8M7N (250 - 355 lm min.)
Rated voltage: typ. 3.05 V (min. 2.75 V, max. 3.75 V)
Forward current: 50 to 1,500 mA
Surge current (10 µs): 2,500 mA
Viewing angle: typ. 120° (at 50 % Iv)
Chomaticity coordinates acc. to CIE1931: typ. Cx 0.33 / Cy 0.34
Thermal resistance: typ. 4.3 °C/W (max 5.5)
Junction temp.: max 150 °C
Junction temp for short time applications: max 175 °C


The official datasheet can be found here (download starting by click on link, offficial Osram website, pdf)


Optical / electrical simulations and CAD files can be also found at Osrams homepage.




First appearance



The Oslon Black Flat is a 3.75 x 3.75 x 0.5 mm LED. The housing is made of black epoxy which has every Oslon Black LED. Because of the domeless design the Black Flat appears very flat, like the name says.





The yellow LES is embedded in a white area which offers a great avdantage in the mechanical stability – the risk of damaging a silicon layer or dome in case of mishandling is greatly reduced.





The Black Flat has a thermal pad, which is unfortunately NOT electrically isolated, a very annoying feature which makes soldering on DTP boards more complicated. It requires that the board or the driver is mounted electrically isolated from the flashlight body otherwise the LED will run in direct drive mode and maybe could destroyed or the life span is greatly reduced.

Despite Osram using an own footprint type (3030), the Black Flat fits on XP boards. The emitter doesn’t seat itself, and it is strong recommended not using too much solder paste that squeezes out sideways in reflow procedure and cause shorting the contacts.




LED chip and die



The Black is based on the Osram UX:3 platform, the chip was designed in classic lateral style. The white opaque outline doesn’t affect the light at all. In one corner (where the bonding wire is attached) the LES appears like ‚bitten off‘ which should have no influence of the beam.





The whole LES is 1.12 mm² (0.001736 sq in) in size (XP-E2 0.85 mm², XP-G2 old version: 1.88 mm²)




Performance and overcurrent capabilites



25 °C Tsp, unless noted otherwise. In ‚real life applications‘ this values may vary.





Within official parameters

  • At 1,500 mA: 438.9 lm @ 3.11 V
  • Power at rated maximum: 4.67 W
  • Efficiency at 1,500 mA: 94.0 lm/W
  • At 1,000 mA (binning current): 320.7 lm @ 3.00 V – equals to binning 6N


  • Maximum at 5,600 mA, 937 lm @ 3.94 V
  • Power at maximum 22.1 W
  • Sweet spot at 4,000 mA (847.2 lm @ 3.58 V)
  • Power at sweet spot 14.3 W
  • Efficiency at max 42.4 lm/W, in sweet spot 59.2 lm/W


I define the sweet spot as the position in the diagram which gives a good average between light flux, current and efficiency. In most cases it lays roughly 15 to 35 percent lower than maximum possible light flux.


  • In the diagramm it can be easily discerned that the voltage raises sharply, probably due to increasing electrical resistance of the bonding connection wires at highest currents. At such a behavior the burning of this wires can be expected. From this point I cannot recommend the operation at such high currents because it significantly shorten the LED’s lifespan.
  • One sample was destroyed in my previous testing at 5,400 mA (burnt wires), even before reaching it’s maximum flux. For real-life applications with maybe less efficient cooling systems it is also absolutely crucial to check the behavior of Vf rising and the maximum current used for this application, to prevent the LED from self-destroying.
  • The operation with FET-based (direct drive, DD) driver electronics should be avoided because the Vf is relatively low and the absolute maximum current of approx 4,800 to 5,200 mA could be exceeded very easily, depending on the quality and performance values of the battery used.






From now on I using a new method for determining luminance, especially to ensure more realistic values for 'real-life' conditions (flashlight use). The measurements are taken with a new original Convoy C8 SMO reflector, but with same test  setup as previously used in flux measurement.


Reflectivity for reflector 85 %

Transmission UCL glass 97,8 %

Values at 25 °C Tsp, for 85 °C Tsp values are 6 to 14 percent lower, depending on LED

LEDs marked with Warning sign uses old values are still taken with previous method (determining die size) due to problematic light distribution (donut holes etc).





In the last months the Black Flat has become a very popular choice for ultra-long range lighting systems (throwers) due to it’s very high luminance which currently represents the maximum of commercial available (and not expensive) emitters. The luminance is approx 22 percent higher as of the old dedomed XP-G2 S4 and approx 45 percent higher than of the highest bin XP-L HI (V3).




Light quality and behavior in optics



In general, there are no issues for using this LED in smooth or peeled reflectors, even with (aspheric) lenses. The notch in one corner of the LES does not affect the beam pattern at all even you can see it if used with aspheric lenses. Because of the high luminance and very small LES it is absolutely necessary to center this LED as precisely as possible to ensure a nice beam pattern.

Like other LEDs with high luminance the tint is a blueish cool white. Even compared to standard 70 CRI light sources (XP-L / XM-L2 cool white used often in flashlights) the color rendition is very low due to very low flux in cyan / deep red, so red and green are not good reproduced which is still normal for cool white light sources in this color rendering class.






The Black Flat features the highest luminance of all commercial available LEDs to date, which makes it extremely interesting for special applications where the absolute throw is desired. Also the beam pattern is good, even in SMO reflectors.

Due to it’s own Osram 3030 footprint the reflow procedure is a bit more difficult as we know from classic XP LEDs, and the tint is a blue cool white with no good color reproduction which should be negligible for this application.
Also I did not like the electrical connected thermal pad which makes the use of DTP boards more complicated.




  • Highest luminance of single LED to date (March 2018)
  • Good beam pattern if used in conjunction with reflectors / lenses
  • Fits on XP boards



  • Cool white option only
  • does not deliver highest flux



  • Electrically connected thermal pad
  • No industry-standard 3535 footprint


Thanks a lot for reading! Smile

Greetings, Dominik (aka BLF member koef3)



Mistakes, suggestions or offers / sponsoring of LEDs which I should test next are best sent via PM.


My LED tests: --- Nichia 319AT 83 CRI - Lumileds Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

Last seen: 54 min 29 sec ago
Joined: 05/14/2017 - 11:16
Posts: 1641
Location: Ślōnsk

Thanks for the test!
Would it be possible to get raw output from your tests? I’d like to draw some charts of my own…

djozz's picture
Last seen: 1 hour 44 min ago
Joined: 09/07/2012 - 17:04
Posts: 11763
Location: Amsterdam

Thanks for the test!

You measure a bit higher max at a bit higher current than my test two years ago, which probably proves again the imperfectness of the cooling of my led-mount. But another possibility is that this led has got slightly better specs in those 2 years.