Choosing a Bicolor LED Supplier: 2-Pin vs 3-Pin and Binning Pitfalls
Quick answer: bicolor LEDs are two dies in one package — qualify a supplier on per-die binning and color pairing, not just the package. Unbalanced dies make one color dominate, the classic bicolor complaint.
Pin Types to Specify
- 2-pin inverse-parallel: color depends on current direction; simplest wiring.
- 3-pin common cathode: common pin to GND, drive each color high.
- 3-pin common anode: common pin to V+, sink each color low.
The Binning Pitfall
Red dies (~2.0 V) and green dies differ in efficiency. Without per-die brightness binning and deliberate wavelength pairing, mixed reds and greens in one housing look uneven — especially when both dies are lit to make yellow. Ask how the supplier pairs dies.
What to Fix in the Spec
- Color pair by wavelength (e.g. 625 nm red / 570 nm yellow-green) or true-green requirement.
- Brightness bin per die at your actual drive currents.
- Package and lens: 3mm/5mm through-hole, 0603/1615 SMD, diffused for panels.
- Pinout drawing for 3-pin types — anode/cathode orientation is not universal.
Hongcheng Optoelectronics, a member of Guangyu Group, is a 20+ years LED packaging manufacturer with 40 automated ASM lines and 200KK pcs monthly capacity. Free samples and PDF datasheets are available in our datasheet center; browse the product center or contact us for a bulk quote. Bicolor options across our SMD and through-hole series.
