Light Emitting Diodes: SMD, Through-Hole, IR and UV LEDs
Light-emitting diodes for indicator, PCB and optical designs
This collection concentrates on component-level LEDs rather than complete household lamps. It includes miniature surface-mount devices, 3 mm and 5 mm through-hole indicator diodes, rectangular 2 × 3 × 4 and 2 × 5 × 7 mm packages, side-emitting chips, bicolor and RGB selections, infrared and ultraviolet emitters, high-power IR devices and one reflective optical sensor family. Choose the exact package, emitted color or wavelength, lens, electrical rating and quantity in the selected variant. A listing that names red, green, blue, warm white and RGB is normally presenting alternatives, not a promise that every diode can produce every color.
Understand what the package number means
0402, 0603, 0805 and 1206 are familiar compact SMD form-factor names; the catalog also includes 1210/3528, 2835, 3014, 4014, 5050 and 5730-style packages. Similar marketing dimensions do not prove the same land pattern, polarity marking, height, side-versus-top emission, luminous output or heat path. A 020/3806-style side-luminous part directs light differently from a conventional top-emitting 0603. “0603” can refer to a 1608 metric package in many listings, whereas other seller labels use ambiguous dimensional conventions. Consult the selected item's mechanical drawing or measured footprint before committing a PCB pad layout.
Reel products may specify 3,000 or 4,000 pieces; cut quantities include 20, 50, 100, 200 and 500 pieces, while assortment books can contain 750, 1,000 or 1,200 pieces across multiple values. A 100-piece Red selection, a 100-piece five-color mix and a full reel of one color are different deliverables. Count the selected variant rather than the largest number in a listing headline. Verify tape-and-reel orientation, reel diameter, moisture/reflow handling and bin consistency with the specific listing before planning automated placement; bulk bagged LEDs should not be assumed pick-and-place ready.
Miniature SMD LEDs: 0402, 0603, 0805 and 1206
These compact indicators suit PCB status signals, front-panel light pipes, compact displays and model-making where board area matters. This assortment contains separate red, yellow, orange, emerald or true green, blue, ice blue, purple, pink, warm-white, white and UV-marketed options. Some 0402 products list a common-anode RGB variant alongside simple single-color two-terminal chips; these are not interchangeable footprints or drive schemes. A 0603 red/warm-white bicolor device and a 0603 red/green/yellow common-anode device likewise require different terminal mapping and channel control. Choose by actual pin count and polarity, not just body size or visual color in a photo.
Some 0603 and 0805 items are sold as multi-value sample kits or color mixes. A label such as “five colors × 20 pieces” describes the package composition, whereas “Blue 100pcs” identifies a single-color lot. For 1206, 3528 and 5050, a title that lists UV and RGB alongside ordinary single-color selections covers materially different junction structures. A fixed warm-white 1206 LED does not blend RGB colors; an RGB LED is not automatically individually addressable. No microcontroller, series resistor or controller is implied by a loose SMD chip purchase.
2835, 3528, 5050 and 5730 emitter families
These larger SMD parts appear in single-color red, green, blue and white options, as well as warm/natural/cool white, ice-blue, UV and some RGB variants. One 2835 listing offers 3000 K warm, 4000 K natural, 6000 K pure and 9500 K cool selections, while another separates 3, 6, 9, 12, 18, 36 and 54 V-marketed emitter choices with 0.5/1 W and 50/100-piece options. These are selected configurations, not a universal voltage range that any 2835 LED accepts. Some 3528 red devices are described near 620–625 nm, while purple/UV listings may specify 365 or 395 nm; wavelength and forward voltage belong to those specific selections, not all members of the series.
Chip power class, measured luminous flux, current, forward voltage and thermal resistance must be read together. Marketing claims like “3 V,” “0.2 W,” “0.5 W,” “1 W,” “23–26 lm” or “120 lm” may describe different chips or different operating conditions. A 5050 RGB package contains separately driven junctions; a 5050 monochrome diode does not become RGB when placed next to other colored options. The package dimensions alone are insufficient for pad compatibility, reflow profile, polarity or lens orientation. Use actual product-level electrical and mechanical specifications and allow appropriate current limiting and heat removal.
Through-hole indicators and rectangular LEDs
Round 3 mm/F3 and 5 mm LEDs are available as clear or diffused lenses, flat or domed profiles, short-lead lots and assorted packs. A flat-top style can spread light differently from a clear round lens; red, green and blue clear-body LEDs may look similar until powered. The collection also contains rectangular transparent 2 × 3 × 4 and 2 × 5 × 7 mm options in separate colors. Match body shape and bezel or light-pipe geometry as well as color. Do not assume long lead always denotes the anode after leads have been trimmed, or that the same lead layout applies to a three-pin multicolor version.
Some 5 mm products are self-flashing RGB or blinking single-color parts. Their internal oscillator behavior is different from a plain continuous diode or a multichannel RGB LED under external control. A 5 mm assorted kit is not automatically a calibrated color bin set. Select the precise color and packaging count, then check the device's forward current, forward voltage, reverse limits and viewing angle. A bare LED is a current-driven semiconductor junction, not a device to connect directly to a supply named by its approximate forward voltage.
Infrared emitters versus optical sensors
5 mm IR options include nominal 850 and 940 nm variants, with some packages offered as 100, 200, 500 or 1,000 pieces. Other IR listings specify 740, 850 or 940 nm and 60, 90 or 120 degree viewing-angle choices in a 3 W-marketed high-power family, with single-unit or multipack selections. Nominal wavelength, radiant intensity, optical angle, forward current and thermal mounting are different engineering quantities. An 850 nm source can show a faint visible red glow in some circumstances; a 940 nm selection may appear less visible, but neither is eye-safe merely because the beam seems dim. Camera sensor sensitivity, optics and exposure determine application performance; “night vision” is not a universal compatibility claim.
The TCRT5000/TCRT5000L-style listing is a reflective sensing component combining an IR emitter and phototransistor receiver. It is not simply another standalone light source. The “12M” phrase in a seller headline must not be treated as a verified 12-metre detection range for a reflective sensor; detection depends on geometry, reflectance, ambient light and circuit design. Check the actual part variant and pinout before designing a proximity or line-following board.
UV, violet and nonvisible-light choices
Surface-mount 0805 chips advertised near 395–400 nm and 2835/3528 options near 365 or 395 nm require wavelength-specific optical review. “Purple” visible light and UVA-marketed LEDs are not automatically the same emission band. Visible brightness is an unreliable indication of ultraviolet or infrared exposure. Use application-appropriate enclosure and eye/skin precautions, and verify radiant-output and spectral information for the exact product if required. A seller's generic certification wording or color label is not evidence that every UV or IR variant is certified for a particular medical, sterilization or security task.
Electrical design and assembly checklist
- Select the intended device: top-emitting SMD, side-emitting SMD, through-hole indicator, rectangular LED, bicolor/RGB emitter, high-power IR LED or reflective sensor.
- Read the full variant: package code, color/wavelength, voltage/power designation and quantity; do not combine specifications from neighboring variants.
- Verify drive conditions: current, forward-voltage range, reverse-voltage limit, polarity/pinout and resistor or constant-current driver requirements against the selected emitter's reliable specifications.
- Plan optics and heat: lens diffusion, viewing angle, light-pipe coupling, board copper, thermal resistance and permissible operating current; nominal wattage does not replace a thermal calculation.
- Confirm manufacturing details: pad land pattern, reel versus loose packing, orientation, soldering process and lot/bin consistency for repeatable production.
- Apply appropriate optical safety: particularly with high-power IR and near-UV sources, where appearance alone cannot quantify exposure.
These are components for engineered assemblies. The presence of one listing with a stated wavelength, luminous flux, certification, lifetime or voltage does not extend that claim to every item in this collection. Compare the selected product page, actual variant and any trustworthy datasheet before specifying a design.
