2835 LED for U.S. Buyers (2025): Meaning, Real Wattage, Dimming, SMD Basics & 2835 vs 5050

2835 LED Explained: Watts, Dimming & 2835 vs 5050 (2025)

Plain-English answers for U.S. wholesale buyers: what 2835 means, how many watts it really draws, dimmability, SMD basics, and whether 2835 or 5050 is brighter—plus RFQ-ready specs.

Problem — Vendor pages shout “SMD 2835 high-efficiency,” but skip the numbers you need to quote confidently and avoid RMAs.

Agitate — Choose wrong and you’ll overheat strips, fight flicker on dimmers, and ship zebra-striped shelves—while your competitor locks the re-order.

Solution — Use the five buyer-grade answers below (with copy-ready RFQ lines) to spec 2835 correctly the first time—no surprises, no excuses.

Know the package, calculate true watts, dim without flicker, reflow SMDs right, and choose 2835 or 5050 by $/klm—not brochure hype.

If you’re a New York–based wholesale buyer, your Google history probably reads like this: “What does 2835 LED mean?”, “How many watts is a 2835?”, “Is 2835 dimmable?”, “What does SMD mean?”, and “Which is brighter, 2835 or 5050?” Those five questions decide whether your next rollout ships smooth—or collapses into overtime installs and returns.

Here’s the fast orientation for 2025:

2835 = 2.8 × 3.5 mm footprint. A mid-power SMD package with an exposed thermal pad that dumps heat into copper. Modern Ra80 bins routinely hit high lm/W around 65 mA; Ra90 options trade a little efficacy for better reds (R9)—perfect for retail and medical-beauty applications.

Watts aren’t printed on the case. Power is I × Vf. Push current without improving the thermal path and a brochure “0.2 W” quietly becomes 0.36–0.5 W, slicing lifetime.

Dimming is fine when drivers meet IEEE 1789 guidance (Percent Flicker / Flicker Index) and the phosphor mix doesn’t smear color at low duty.

SMD means surface-mount device: reflow-soldered parts that lower labor and improve thermals—if your stencil, paste, and reflow profile keep voids low.

Brightness reality: 5050 wins per-package punch and rules RGB; 2835 often wins $/kilolumen and heat spread on dense white strips.

1·Size Code, Not Hype: 2835 in One Sentence

“2835” is the package size—2.8 mm × 3.5 mm—a mid-power format balancing lm/W, strip density, and a solid heat path.

Problem. Teams treat “2835” like a brightness grade and mix reels assuming they’re interchangeable.

Agitate. Mixed packages and chemistries create tint mismatch, hot spots, and reflow headaches.

Solution. Treat 2835 as geometry. Inside: a single InGaN die on a reflective silver leadframe, phosphor, and an exposed slug that solders to copper. The format shines on 8–12 mm strip PCBs at 120 LED/m: smooth diffusion, controllable thermals, high first-pass yield. In 2025 bins, Ra80 whites commonly achieve high efficacy at ~65 mA; Ra90 options sacrifice some lm/W for R9 ≥ 50, crucial for cosmetics, produce, and fashion. Lock visual uniformity with ≤3 SDCM (general) or ≤2 SDCM (retail/cameras). Ask for native LM-80/TM-21 and EN 62471 PDFs (ISO/IEC 17025 labs) to keep audits and buyer due diligence painless.

What to specify—clearly and early:

Thermal: RθJC ≤ 12 °C/W; staggered micro-vias under the slug; 2-oz copper on FR-4, or MCPCB for higher power.

Materials: silver mirror reflectivity with anti-sulfur encapsulant for leather/rubber environments; see sulfur-safe checklist.

Phosphor uniformity: require Δu′v′ stability plots over time and temperature; template: color-drift tracker.

Polarity & pads: share pad file and stencil card up front; reference: 2835 pad drawing.

RFQ copy: “2835 package 2.8×3.5 mm, exposed thermal pad; RθJC ≤ 12 °C/W; ≤ 3 SDCM (≤ 2 optional); anti-sulfur encapsulant; provide native LM-80/TM-21 & EN 62471 PDFs.”

2·Wattage Math: Stop Calling Every 2835 “0.2 W”

Watts = I × Vf. Current, voltage, and the heat path—not a catalog blurb—decide lifetime.

Problem. Catalog “0.2 W” gets dropped onto a board and then driven at double current.

Agitate. Junction temps spike; L70 collapses; white drifts green; RMAs hit your inbox.

Solution. Use your actual driver current and the supplier’s Vf histogram to compute Pd = I × Vf. Example: 65 mA × 2.9 V ≈ 0.19 W (catalog). Push to 120 mA × 3.0 V ≈ 0.36 W—fine on MCPCB, risky on thin FR-4 where heat bottlenecks. Estimate ΔT = Pd × RθJC and add board-to-ambient to get Tj. Keep Tj ≤ ~105 °C for stable lumen and color. Want more flux? Under-drive and add emitters; strip efficacy rises and hotspots vanish. Cap driver ripple < 5 % so peak current doesn’t quietly over-stress the die.

Controls that stabilize watts:

Vf window: specify typ 2.8–2.9 V; max 3.1 V @ 65 mA and demand the distribution, not just min/max; see Vf primer.

String balance: prefer series; if you must parallel, add balancing resistors to prevent current hogging.

Driver topology: constant-current buck with spread-spectrum PWM reduces EMI and current peaking.

Substrate step-up: crossing ~0.30–0.36 W per LED? Move to MCPCB before your junction cooks; checklist: thermal upgrade guide.

RFQ copy: “Quote lm/W at 65 mA and at our max current; provide Vf histogram, RθJC data, and ΔVf after 1 000 h @ 85 °C/IFnom.”

3·Dimming That Doesn’t Flicker (or Shift Color)

Use 2–4 kHz PWM or CCR, and verify IEEE 1789 metrics plus low Δu′v′ at low duty.

Problem. Constant-voltage strips on triac wall dimmers create ripple and camera banding.

Agitate. Hospitality staff report eye-strain; reviews mention flicker; you absorb returns.

Solution. Pair 2835 with PWM ≥ 2–4 kHz or CCR for sensitive sites. Put two limits in writing: Percent Flicker < 10 % and Flicker Index < 0.05 at 100 % output; then test at 20 %, where cheap drivers spike. Ask for a phosphor decay curve; fast-decay mixes track PWM better, while slow-decay can hide strobe but warms CCT. Require Δu′v′ ≤ 0.003 from 100 % → 10 % at Tc 25/55 °C so whites don’t wander on camera.

Dimming checklist you can hand to engineering:

Driver — PWM (≥2 kHz) or CCR; add a shunt FET to prevent ghosting <2 % duty.

EMI — choose spread-spectrum modulation to tame RF noise and waveform peaking.

Metrics — capture Percent Flicker, Flicker Index; add Pst_LM/SVM if the job spec requires.

Layout — short LED-to-driver traces reduce ringing; good grounds cut surge stress.

References: flicker cheat-sheet • low-duty SOP.

RFQ copy: “Provide IEEE 1789 metrics and Δu′v′ vs dim level on our driver; attach scope screenshots at 100 % and 20 % output.”

4·SMD Means Faster Builds—If Your Reflow Is Right

SMD = surface-mount device: lower labor, better thermals—if stencil, paste, and profile keep slug voids low.

Problem. “One stencil fits all” invites voids and tombstoning on 2835 pads.

Agitate. Voids raise RθJA and shorten life; skew kills yield; timelines slip.

Solution. For 2835, use 0.12–0.15 mm stencils, type-4/4.5 paste, ramp < 3 °C/s, peak 245 ± 5 °C (nitrogen preferred). X-ray first articles: if void area under the slug exceeds ~30 %, tune apertures or add a soak segment. Choose no-clean flux to avoid moisture pockets under lenses; bake PCBs stored > 6 months. Share a one-page reflow card before the first run.

Shop-floor specifics:

Area ratio ≥ 0.66 for consistent paste transfer; step the thermal pad if needed; see SMT setup card.

Aperture reductions limit float and skew; align paste bricks with copper fill.

IPC-7093 sampling—reject lots with repeat void hotspots; adjust soak or peak time.

Cleaning—avoid water-soluble flux under lenses; if used, validate wash and bake cycles; guide: void-control tips.

RFQ copy: “Provide pad layout, stencil guidance, max void %, and recommended reflow curve for the quoted 2835; confirm IPC-7093 compliance.”

5·Brightness Showdown: Package Punch vs Strip Economics

Per package, 5050 is brighter; per $/klm on dense white strips, 2835 usually wins. RGB? 5050 still rules.

Problem. Teams compare single-package lumens and ignore strip-level economics.

Agitate. You overbuy 5050s, BOMs swell, drivers run hot, and hot-spots show through diffusers.

Solution. Normalize to $/kilolumen and consider density. A single white 5050 (often multi-die) can output strong lumens at ~150 mA, out-punching a 0.2 W 2835 at ~65 mA. But eight 2835s spread heat, sustain lm/W, and often beat three 5050s on $/klm once driver channels and freight/duty are counted. For RGB, 5050’s tri-die architecture is non-negotiable. For outdoor “punch,” 5050 white works—just derate current ~20 % for heat and add surge protection.

Decision matrix:

Retail/task/appliance → 2835 white, ≤3 SDCM (≤2 premium), Ra80/Ra90 per channel.

Stage/architectural RGB → 5050 (addressable or non-addressable).

Outdoor signage → 5050 white + thermal derating + robust surge control.

Supply risk → 2835 whites are widely second-sourced; addressable 5050s may lock you to one IC vendor.

Tools: $/klm calculator • 2835 vs 5050 matrix.

RFQ copy: “Quote 2835 white (Ra80 & Ra90) and 5050 white/RGB as $/pc and $/klm landed (FOB & DDP NY). Include SDCM, RθJC, IEEE 1789, and surge limits.”

Binning: ≤ 3 SDCM (≤ 2 premium); shipment ≤ 2 adjacent bins; reel cert lists CCT, Duv, Ra, R9, lm, Vf, lot.

Thermal & Reliability: RθJC ≤ 12 °C/W; HTOL 1 000 h @ 105–125 °C, 85/85 1 000 h, –40↔125 °C 1 000 cycles, surge 10/700 µs to 2 kV; lumen loss ≤ 10 %, ΔVf ≤ 0.1 V, Δu′v′ ≤ 0.006.

Dimming: Provide IEEE 1789 metrics; Percent Flicker < 10 %, Flicker Index < 0.05 at 100 %; verify at 20 %.

Pricing: Quote $/pc and $/klm landed (FOB Shenzhen & DDP New York); itemize bin premiums; include NET-30/NET-60 scenarios.

Optional FAQ

What does 2835 LED mean?

The 2.8 × 3.5 mm SMD footprint—mid-power package with an exposed thermal pad.

How many watts is a 2835 LED?

Depends on current and Vf. Catalog “0.2 W” assumes ~65 mA; push current and you’re at 0.36–0.5 W.

Is 2835 LED dimmable?

Yes—with 2–4 kHz PWM or CCR and verified IEEE 1789 metrics.

Which is brighter, 2835 or 5050?

Per package, 5050. On dense white strips and $/klm, 2835 often wins; RGB still belongs to 5050.

Want this turned into a printable warehouse QC checklist or a one-page $/klm calculator?

Send your CCT/CRI, drive current, and incoterm. XGM will ship matched-bin 2835 samples plus native LM-80/TM-21 and EN 62471 PDFs—so you can evaluate today and issue a confident PO tomorrow.