2024-02-26
Some time ago, a special LED appeared on the Fireflylite website. This LED, presumably manufactured for Fireflylite at customer’s request, is very similar to the well-known ‘Yinding 5050 egg-yolk’ and should therefore offer a high luminance with very decent light quality. It is therefore referred to here as the Fireflylite FFL505A.
A special feature here is the actively advertised reddish tint (“rosy-tint”) and the very high color rendering of 95 CRI.
This LED was made available to me for this test by BLF user @MarcE. Many thanks for that!
Tj --- °C, If --- mA
- Type: single die, lateral
- Bin: —
- Color group: 3500 K (‘rosy’)
- CRI: 95
- Rated voltage: — V
- Max. Forward current: — mA
- Max. Peak current: — mA
- Viewing angle: — °
- Thermal resistance: — K/W
- Max. Temperature Tj: max. —°C
Important note: An official data sheet and further information are not available for this emitter. Official data can therefore not be provided during the test.
The FFL505A is extremely similar to the well-known ‘Yinding 5050 egg-yolk’. This LED is presumably manufactured by the same manufacturer as the ‘Yinding 5050 egg-yolk’ on behalf of Fireflylite, hence the name “FFL505A”.
The white SIlikon surrounds the orange-colored round illuminated area. This is more reminiscent of a PC Amber LED than a warm white LED with 3500 K CCT. It does not protrude from the silicone, but is embedded in it. The four bonding wires are also cast into the silicone and are only visible under good lighting conditions. The substrate is dark gray; there are no other conspicuous features. All in all, it is an extremely simple designed LED, which could be an advantage depending on the application.
There are no other inscriptions or markings on the top. The white silicone is relatively brittle, which is why the LED must be handled with care.
The FFL505A measures 4.98 x 4.98 mm.
The footprint offers no surprises. Thanks to the XM or 5050 footprint, it is compatible with accessories for this format and can therefore be retrofitted in many lamps. Thanks to the symmetrical housing, centering rings manufactured on a lathe can also be used.
The notch in the contact indicates the cathode.
The luminous area is 2.35 mm² in size.
Due to the very rosy tint, the illuminated surface is downright pink in color at very low current. Clear dots and speckles can be seen on the luminous surface, which can be observed with many HighCRI LEDs. Discoloration or artefacts are otherwise not visible on the luminous surface, which should improve the quality of light in secondary optics.
Within official parameters, as far as known:
- Maximum reached at 8.8 A, at this point 984 lm @ 3.62 V
- Power at maximum 31.8 W
- Efficiency at maximum 30.9 lm/W
Due to a lack of official performance information and data sheets, no official maximum values were specified. However, some observations can be made.
The FFL505A is probably the most inefficient modern LED in the 5050 footprint that has ever been tested. At just 30.9 lm/W at maximum possible current, it is even less efficient than an over-current halogen lamp (36 lm/W)! An LED has obviously been designed here that completely subordinates its efficiency to the goal of a rosy tint, and this is even more extreme than with the SFT-40 3000 K (test here). The SFT-40 benefits above all from the larger illuminated area and better heat dissipation, which fully utilizes the thermal pad of the 5050 footprint.
More than 800 to 850 lm is hardly feasible in a flashlight. Even at over 6 A, the heat development increases so much and the luminous flux gain is so low that further overcurrent is simply not worthwhile.
It should be noted that the luminous surface of the FFL505A is very small for a 5050 emitter. Although LEDs with very small luminous surfaces offer a higher luminance, they have a lower luminous flux and are generally less efficient. This is where the factors of small luminous surface and extremely rosy tint and warm light color come together.
The Vf is pleasingly low and is in the range of the Nichia 519A and SFT-40 3000 K. Direct-drive (operation of the LED without a driver directly on a battery) is not recommended due to the sometimes very high voltage level and can lead to the destruction of the LED or to a significant reduction in service life.
Data for 25 °C Tsp (at 85 °C the luminance values are around 13 % lower).
As expected, the luminance is quite high for its low luminous flux, at 2.8 A it is significantly higher than that of the warm white SFT-40. Nevertheless, all other LEDs with a similar round chip have a significantly higher luminance. The low luminous flux also plays the main role here.
The beam is perfect. There are no artifacts due to the round illuminated surface and the lack of lateral radiation. Rings can occur depending on the reflector used and the quality of the surface and production. These no longer occur in OP reflectors anyway. There are no color distortions. Any discoloration in the photo is not visible in real life and is caused by the camera.
The LED tested here is extremely rosy (350 mA operating current). The tint is very strongly reddish. Even Nichia LEDs generally have a less intense red tint.
The red component is extremely high. Even at 670 nm, the radiant power is still over 60 %. The high proportion in the range above 700 nm, which is very rare for LEDs, is also striking. In addition to the extremely thick phosphor layer, this is presumably the reason for the extreme inefficiency - a large proportion of the light is emitted as deep red (also sometimes called far red), well below 660 nm - a wavelength that is often used in Photo Red or Deep Red LEDs.
Due to the extreme red tint, the light appears significantly warmer than it actually is. At 3845 K, it is almost in the neutral white range, but still appears warm. Red and brown tones are massively emphasized, making it difficult to distinguish between grey and green tones. This light is not realistic in the sense of naturally occurring light.
The specified CRI of 95 is not achieved. The Rf of 106 indicates a clear oversaturation of the colors. Depending on your preference, this extreme red tint may be too much of a good thing. Before using this LED, you must be aware that the light does not necessarily correspond to what Nichia is known for.
With increasing current, the tint shifts more to the colder side and the duv is also increasing. This looks much more appealing to the human eye.
Although the light appears colder and more pleasant at first glance, this significant tintshift should be viewed critically, as it could possibly result in a significant reduction in service life at such high currents. This is particularly problematic as there is no official data sheet and therefore no official maximum current as a guideline.
- Ra: 92
- R9: 75
- CCT: 3845 K
- duv: -0.0135
The FFL505A is a custom LED that could have come straight out of a groupbuy by flashlight enthusiasts. Extremely rosy tint, low Vf, high luminance and perfect beam quality. In principle, it does a lot of things right.
However, the efficiency is extremely low and even undercuts over-current halogen lamps at maximum luminous flux. Even at over 8 A, more than 1000 lm cannot be achieved. In addition, not everyone will like such an extremely reddish tint.
An improved FFL505A with the same round-die, but a less strong red tint (duv max. -0.007) and a more balanced spectrum, which has a higher efficiency, could be close to the ideal case of a warm white LED and could be a very popular LED for many enthusiasts. However, this requires the availability of a simple source of supply and an official data sheet.
Pro
- very good beam
- standard XP-/5050 footprint, good compatibility with accessoires
- low Vf
- relatively high luminance for warmwhite High CRI LED
Neutral
- very reddish tint (‘rosy’)
Contra
- very low light flux
- very low efficiency
- no reliable information on the LED publicly available (as of Feb. 2024)
- only available in China or from Chinese sellers
Thank you for reading the test. 
