LED test / review
EN

Nichia NVSW319AT sm503 D400f2 R8000

Technical data

Tj 25 °C / If 1,050 mA unless noted otherwise

Order code: ---

Type: single die (Flip Chip)
Binning: D400f2
Rated voltage: typ. 3.02 V
Forward current: max. 2,000 mA
Peak forward current: 2,400 mA
Viewing angle: 135 °
Color Rendering Index Ra: min. 80, typ. 83 (R9: 0)
rated CCT: 5000 K
Thermal resistance: typ. 3.0 °C/W (max 4.0)
Junction temp.: max. 150 °C

The official datasheet can be found here (pdf, official Nichia website)

Appearance and LES

For larger pictures: on image right-click, 'View Image'

Unlike other LEDs this emitter features a special hexagonal LES. This should improve the beam pattern and color uniformity in secondary optics, especially for SMO reflectors. The white marking (on picture left upper corner) marks the cathode.

Like most other Nichia x19 series the footprint is almost the same as known from XP LEDs, so the whole range of accessoires (boards, center rings / isolators) can be used.

The both electrode pads (Au plated) next to the bigger thermal pad are smaller than of other XP based LEDs which could be a problem at highest currents.

The whole LES has no miscolored areas so a uniform color distribution (color over angle) in optics can be expected.

Thanks to the Flip Chip design there are areas which emits light to the side, a feature already known from XP-L2, Luxeon V 2017 and many other LEDs which uses this fairly common LED chip technology.

The die is 5.72 mm² (0.00887 sq in, only top view) in size.

Performance and overcurrent capabilities

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

Within official parameters

• At 2,000 / 2,400 mA (max rated / peak): 743.8 lm @ 3.10 V / 852.9 lm @ 3.14 V
• Power at rated maximum (max / peak): 6.20 W / 7.54 W
• Efficiency at 2,000 / 2,400 mA (max / peak): 120.0 lm/W / 113.1 lm/W
• At 1,050 mA (binning current): 438.8 lm @ 2.96 V

Overcurrent:

• Maximum at 7,800 mA, 1,592 lm @ 3.46 V
• Power at maximum 27.0 W
• Sweet spot at 4,600 mA (1,318 lm @ 3.30 V)
• Power at sweet spot 15.2 W
• Efficiency at max 59.0 lm/W, in sweet spot 86.7 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.

• the 319AT is a nice efficiency upgrade from the 219C if the bigger LES is suitable for the application.
• The thermal resistance of the old 219BT-V1 is much higher so the maximum performance possible is also less
• The XP-L HD V5 (shown in diagram for better comparison) is much more efficient. At 5,800 mA it delivers approx 30 percent more light.
• In general it seems that the 319AT has a slightly better heat dissipation as the 219C.

Luminance and color quality

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).

The luminance of 219C and 319AT are almost the same. The gain in efficiency and light flux is therefore due to larger LES and slightly better heat dissipation, not because of higher luminance. From this point I cannot recommend this LED for ultra-long range flashlights (throwers).

Like the naming 'sm503' designates this LED was binned in 3-step MacAdams ellipse. Like already known from Nichia emitters, the tint is a pleasant neutral white without much color shift to yellow or green, at least at higher currents. At lower currents, even under 700 mA, the tint shifts slightly to the yellow side. The CRI is higher than of other (70 CRI) LEDs so the manufacturers claim of typical 83 CRI should be true.

The side LES does not affect the color distribution at all, so this LED in general can be easily used in optics, even in SMO reflectors (in picture I used the Convoy C8 SMO reflector).

Conclusion

An interesting LED, thanks to unsual hexagonal die. It is more efficient than the 219C in same color rendering / CCT class. The color uniformity in beam is also very good, like the tint (even at higher currents).

The luminance is not as high, but this can be expected from a domed LED. Unfortunately the tint shifts visible to yellow at low current (CC regulated, not PWM). Overall a good LED for using in flashlights, with no significant weaknesses.

Pro

• Higher efficiency
• Hexagonal die for uniform beam and color distribution in optics
• nice tint (at higher currents)
• higher color rendition

Neutral

• visible tint shift to yellow at lower currents (CC)
• could be difficult to buy, like most Nichia emitters
• maximum performance not as high compared to other LEDs in same power rating

Con

• still no high CRI option available

Thanks a lot for reading!

Greetings, Dominik (aka BLF member koef3)

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