APA102 Pixel Protocol
Manufacturer: APA ElectronicA two-wire clocked RGB pixel that pairs a dedicated clock line with its data line, giving timing-tolerant control over long runs at 5V.
Specifications
| Specification | Detail |
|---|---|
| Clock Type | Clocked |
| Color Resolution | 8 Bits |
| Physical Package | SMD5050 with integrated LEDs |
| RGB | Yes |
| RGBW | No |
| Output Pixel Voltage | 5V |
| PWM Rate | 1920Hz |
| Suitable Camera | Up to 67fps |
| Redundant Data Line | No |
Strengths
- The dedicated clock line decouples data timing from the data rate, so the chain tolerates long runs and is forgiving of cable and refresh variation, which is a genuine strength of clocked protocols.
- An integrated IC in each SMD5050 pixel delivers 8-bit-per-channel (24-bit) RGB for smooth per-pixel colour control and clean gradients.
- At 1920Hz the PWM rate is comfortably flicker-free for the stated camera work up to 67fps, giving sensible headroom rather than an inflated vendor figure.
Limitations
- The second (clock) conductor is a real tradeoff: it adds wiring and cost and another point of failure, and a high-frequency clock line radiates EMI that can cause interference in sensitive installations. The market is trending toward data-only single-wire chips to avoid both, so the timing-tolerance advantage comes at a cost rather than being simply better.
- No redundant data line: a single failed pixel or broken joint interrupts data to every pixel downstream.
- RGB only, with no white channel, and 5V distribution is prone to voltage drop over longer runs, so power injection is usually needed.
Overview
The APA102 is a two-wire clocked RGB pixel: it carries a separate DATA line and a dedicated CLOCK line, unlike self-clocking single-wire chips such as the WS2812. Each 5V pixel houses an integrated IC in an SMD5050 package and drives 8-bit-per-channel (24-bit) RGB at a 1920Hz PWM rate, comfortably flicker-free for camera work up to 67fps. The clock line keeps data timing tolerant over long runs, though there is no redundant data line. ENTTEC pixel controllers drive a wide range of pixel protocols; contact ENTTEC about chips not listed. ENTTEC is not affiliated with APA Electronic.
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.