WS2818A Pixel Protocol
Manufacturer: WorldsemiA single-wire, individually addressable 5V RGB pixel protocol with an integrated 8-bit driver IC and a backup data line for break-point resilience.
Specifications
| Specification | Detail |
|---|---|
| Clock Type | Data-Only |
| Color Resolution | 8 Bits |
| Physical Package | SOP8 |
| RGB | Yes |
| RGBW | No |
| Output Pixel Voltage | 5V |
| PWM Rate | 2000Hz |
| Suitable Camera | Up to 67fps |
| Redundant Data Line | Yes |
Strengths
- Redundant (backup) data line means a single failed pixel does not necessarily kill the rest of the run, a genuine advantage for long installs where a break-point would otherwise dark out everything downstream
- Single-wire, self-clocking design needs only one data conductor plus power and ground, keeping cabling and connector count low
- 2000Hz PWM is comfortably flicker-free at the rated 67fps, so it is safe for typical on-camera use without over-specifying refresh
Limitations
- As a data-only single-wire protocol the timing is tight and self-clocked: long leads, marginal levels, or electrical noise can corrupt the signal, so injection points and clean 5V distribution matter over distance
- 8 bits per channel (256 levels) is standard-depth colour; slow fades and very low-level dimming can show visible banding compared with higher-bit-depth drivers
- 5V operation causes noticeable voltage drop along a run, so longer strings need regular power injection to hold colour accuracy at the far end
- RGB only, with no dedicated white channel, so pastel and true-white mixes rely on combining the three colours rather than a separate white LED
Overview
The WS2818A is a single-wire, self-clocking RGB pixel protocol from Worldsemi, closely compatible with the WS2812 family. Each 5V pixel carries an integrated driver that latches 24-bit colour (8 bits per channel), regenerates the signal, and forwards the remainder down the chain. Its defining feature is a redundant data line: if one pixel's forward output fails, a backup path lets the rest of the run keep receiving data, improving reliability on long strings. PWM runs at 2000Hz, comfortably flicker-free for cameras up to 67fps. Pixels ship in an SOP8 package. ENTTEC is not affiliated with Worldsemi.
Mapping an installation? ELM, ENTTEC's free LED pixel mapping software, drives the controllers above over Art-Net and sACN, from a single fixture to building-scale maps.
ENTTEC has been engineering lighting control in Australia since 1999, and shipping LED pixel controllers since the original Pixelator in 2014.