0. If you are seeing a specific symptom, start here
This page is written to be read end to end. If you are here because something is already wrong, start below instead. The table maps choosing a package symptoms to the three causes that account for most of them in the field, and to the one measurement that separates them. If the measurement contradicts the table, the cause is outside the range this page covers.
| Symptom you are seeing | The three most likely causes | The one measurement that separates them |
|---|---|---|
| Two candidate packages meet the flux spec, but only one survives the environment | Only one of them is qualified for your ambient and mounting conditions | Check the absolute maximum ratings against your worst-case ambient |
| The part you chose is no longer offered in the colour you need | Colour availability is per series; the footprint is not the constraint | List the colour and CCT you need, then check which series cover it |
| Samples pass, the production batch does not | Sample quantities are hand-picked; production is binned differently | Specify the bin you want and check it on receipt, not on the sample |
Two things to do before you continue production
- Lower the drive current or the duty cycle before anything else. Almost every symptom below is current- or heat-driven, and reducing both is reversible within minutes.
- Measure before you swap parts. A forward-voltage measurement across the assembly, taken with the board powered, separates a driver problem from a LED problem in under five minutes and costs nothing.
When to contact us
Contact us when the measurement contradicts the table, when the same batch shows the same symptom in more than one assembly, or when you need a failure analysis to close a customer case. Bring the bin label, the forward voltage at operating current, and the ambient temperature at the moment the symptom appeared. Send the details to our engineering team.
The chapters below explain the underlying physics and specification in full.
1. How to use this guide
The ceramic line is organised by package, and the package is the first thing that narrows the choice. Within a package the colour, the die count and the drive voltage make the difference between parts that fit the same footprint and cannot be substituted for each other. That structure is what this guide follows: first the package, then the colour, then the electrical configuration, then the application constraints.
The figures quoted here are the ones published on the package pages. Where a handbook series has no corresponding product page, that is stated rather than filled in with a figure from elsewhere. For what the characteristics on these pages mean, see electrical and optical characteristics; for the limits themselves, the absolute maximum ratings; and for the assembly requirements, reliability and soldering.
2. Four questions, in order
A ceramic LED selection is short enough to be four questions. The order matters: each answer constrains the next, and answering them out of order is what produces a part that is overdriven, undriven, or on the wrong voltage band.
Question one is whether the output is visible light, because that decides the whole parameter set. Visible white is specified by correlated colour temperature and, if rendering matters, by Ra. Visible monochrome is specified by dominant wavelength. Ultraviolet and infrared are specified by wavelength and by radiant flux, and the luminous figures on the page do not apply to them.
Question two is flux, and the answer has to be given at a stated current rather than as a number in isolation. A part published at 700 mA and a part published at 1,400 mA are not comparable without dividing the currents out. Question three is power, which sets the footprint: the current and the dissipation together determine what has to be mounted underneath. Question four is the colour mix, and it is the one most often left open, because a single die and a four-channel RGBW part have entirely different channel counts on the same footprint.
3. Package families and what they are for
Four footprints cover most of what is ordered. Each is published with its own current classes, and the power class follows from the footprint and the die configuration together.
The four ceramic footprints, with what each is used for
| Package | Continuous current | Power class | Typical use |
|---|---|---|---|
| 3535 | 350 mA standard, 700 mA high-power | 1 to 3 W | Single-luminaire and directional fixtures; the widest colour and specialty range |
| 5050 | 300 mA standard, 700 mA high-power | 3 to 12 W | Linear and panel luminaires; multi-die and multi-channel designs |
| 7070 | 350 mA standard, 1,600 mA high-power | 5 to 20 W | Flood and high-bay, UV curing, grow lights; the highest continuous current |
| 1860 / 2020 / 2525 / 3030 | lower classes, die dependent | 1 to 5 W | Size-constrained and compact assemblies; orderable via sales |
The 3535 carries the broadest range on the site — monochrome, white, UVA, UVC and UVB, PCR, infrared, far-infrared, bi-colour, and the RGB family — which makes it the default for a design that is not certain about the spectrum. The 5050 is where the multi-channel designs live. The 7070 is the only footprint published above 1,600 mA continuous and it carries the largest dissipation figures, which is why it is used where the fixture can carry the heat away: it is not a desk-lamp part.
One point about footprint size itself is worth stating, because it is the assumption behind most of the table above. A larger package is not simply a scaled-up smaller one. The 7070 page gives a junction-to-ambient thermal resistance of 8 to 12 °C/W on the recommended mounting, and the 5050 page publishes 8 °C/W junction to board; the 3535 publishes no comparable figure at all. Where a thermal resistance is not published, the package still works thermally but the design has to be characterised at board level rather than read off a number. That asymmetry in the published data is itself a reason to prefer the packages where the figure exists, in a design that is thermally marginal.
4. Choosing by colour and by spectrum
Colour is the second filter and it works differently for the visible and the invisible bands. The visible monochrome bands are grouped by forward voltage, which has a direct consequence for multi-channel boards.
Visible monochrome bands, by forward voltage family
| Band | Colours | Dominant wavelengths | Note on use |
|---|---|---|---|
| Low VF | Red, Orange, Yellow | 620–630, 605–615, 585–595 nm | 2.0 to 2.4 V; separate drive rail from the other band |
| High VF | Green, Blue, Purple | 520–530, 450–460, 400–410 nm | 2.8 to 3.6 V; shares a rail with white |
| White | Phosphor-converted | 2200 K to 6500 K | 2.8 to 3.6 V; Ra 70 standard, 80 and 90 available |
| UVA | Ultraviolet A | 365 to 405 nm | Radiant flux in mW; never in lumens |
| UVC / UVB | Germicidal and UVB | by series | Radiant flux; see the 3535 UV page |
| Infrared | IR and far-IR | by series | Radiant flux; see the 3535 IR pages |
The forward voltage split matters mechanically as well as electrically. A four-channel RGBW board assembled from these parts has red and yellow on one voltage band and green, blue and white on the other, so either it needs two regulated rails or it needs a driver that tolerates the difference. This is a design decision made at the board level, and it is visible from the package page data alone.
For ultraviolet and infrared the whole parameter set changes: the figure is radiant flux in milliwatts, the viewing angle is still 120 degrees, and there is no lumen or efficacy figure to compare. The 7070 UVA series is published from 365 to 405 nm at 500, 1,000 and 1,400 mA, which is the reference point for UV work.
5. The catalogue is narrower than the handbook, and that is by design
The handbook describes eighteen ceramic series. The site publishes product pages for the packages listed above. The difference is real and worth stating plainly, because a reader comparing the two will find series in the handbook that have no page here.
The series without a published page — the 2020, 2525, 3030 and 9090 families, and the 5050 white-laser line — are orderable rather than absent. The handbook’s own general notes route custom die configurations, high-voltage series, monochromatic series and special wavelengths through the sales office, and states that product specifications are subject to change. What is not published is not therefore unavailable; it is simply not a catalogue item.
Handbook series against published product pages
| Handbook series | Published page | How to obtain it |
|---|---|---|
| 2020, 2525, 3030 single-die | None | Sales office; low power and size-constrained |
| 3535 mono, RGB, RGBW, RGBY | Yes, nine pages | Direct |
| 5050 mono, multi-die white | Yes, four pages | Direct |
| 5050 white-laser | None | Sales office |
| 7070 multi-die white | Yes, two pages | Direct |
| 9090 multi-die flat | None | Sales office |
The same routing applies to the items a catalogue cannot express: lumen maintenance data for a specific part number, rank and bin selection against a design, and custom die configurations. All four are handled through the sales office, and the handbook states that lifetime claims are not published rather than leaving it to be inferred.
6. The published catalog, by package
The pages below are the ceramic and ceramic-adjacent product pages currently published, grouped by footprint. Every link here has been verified as live.
3535 footprint
- 3535 LEDs
- 3535 UVA LEDs
- 3535 UV LEDs (UVC & UVB)
- 3535 High-Power PCR LEDs
- 3535 infrared LEDs
- 3535 Far-Infrared LEDs
- 3535 Bi-Color White + IR
- 3535 RGB / RGBW / RGBY
- 1860 LEDs
5050 footprint
7070 footprint
7. Worked example: choosing a part for four different requirements
The four questions are easier to apply than to describe. Four requirements work through them and land on different packages, which shows that the sequence is doing real work.
Four requirements walked through the four questions
| Requirement | Visible? | Flux and power | Colour mix | Landing point |
|---|---|---|---|---|
| Single downlight, 4000 K, Ra 80 | Yes, white | 400 lm class, 1 to 3 W | Single die | 3535 white, high-CRI option |
| Panel luminaire, 5000 K | Yes, white | 700 to 800 lm, 3 to 12 W | Single die | 5050 multi-die white, 55 mil x 4 at 6 V |
| RGBW cove lighting | Yes, mixed | per channel low | Four channels | 5050 RGBW; two voltage rails |
| UV curing, 395 nm | No | radiant flux, high VF band | Single die | 7070 UVA at 1,000 mA |
Note the third and fourth rows. The RGBW cove lands on a four-channel part with two voltage rails, which is a board-level consequence of the colour bands rather than a property of any single die. The UV curing row lands on radiant flux at a stated current, and its die sits in the same high forward voltage band as the white parts, which is why the two are not interchangeable on the same driver.
8. Frequently asked questions
Can I substitute a 5050 for a 3535 in an existing design?
Not in the electrical sense, and the footprint difference makes it a board change rather than a drop-in. More usefully, the two carry different current classes: the 3535 publishes 350 mA standard and 700 mA high-power, the 5050 publishes 300 mA standard and 700 mA high-power. Where a design needs the higher dissipation class, the 5050 is the one that reaches it, and that is often the actual reason for the change.
Which package should a high-bay or flood light use?
The 7070. It is the only footprint published above 1,000 mA continuous, carrying up to 1,600 mA continuous with adequate thermal management and 2,000 mA pulsed, and it carries the largest dissipation figures. The corollary is that it needs the heat to go somewhere: the same page states that sustained high-power operation requires active cooling, so the fixture has to be designed for it rather than around it.
Is a bi-colour or multi-die part automatically better?
No. Multi-die raises the flux and the drive voltage together, so it moves the part into a higher dissipation class and usually a higher voltage band. That is a legitimate choice when the flux is needed and the board can drive it, and a liability when the driver, the land pattern or the thermal budget was sized for a single die. Deciding on die count before deciding the driver is the usual cause of a mismatch.
How do I get a part that is not on the catalogue?
Through the sales office, and the handbook says so in its own general notes: high-voltage series, monochromatic series, special wavelengths, other CCT and CRI combinations and custom die configurations are all available on request. The series without published pages are orderable in that way. Anything design-critical should be requested as an individual product datasheet rather than inferred from the family pages.
Can the same footprint take both white and monochrome parts?
The footprint is shared, but the forward voltage bands are not always. Red, orange and yellow sit at 2.0 to 2.4 V while green, blue and white sit at 2.8 to 3.6 V, so a board designed for a mixed colour scheme has to allow for two bands. A board that is strictly white, or strictly monochrome within one band, does not have this constraint.