APA102C Pixel Protocol
Manufacturer: APA Electronic (also known as Shiji Lighting)The APA102C is a two-wire clocked RGB pixel with separate DATA and CLOCK lines, giving stable timing when driven at high data rates.
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
- Two-wire clocked interface: a dedicated CLOCK line means the pixels do not rely on precise self-clocked pulse timing, so the chain tolerates variation in data rate and cabling and can be pushed to high SPI clock speeds.
- 8-bit-per-channel (24-bit RGB) colour from an integrated driver IC, suited to smooth gradients and precise animation along the string.
- 1920Hz PWM is comfortably above the flicker threshold for the rated camera safety of up to 67fps, so it reads clean on typical broadcast and cinema frame rates.
Limitations
- Being clocked, it needs a second (CLOCK) conductor: that adds wiring and cost and another point of failure, and a high-frequency clock line radiates EMI that can interfere in sensitive installations. The timing tolerance is genuine, but the market is trending toward data-only single-wire chips to avoid both drawbacks, so clocked is a tradeoff rather than simply better.
- 5V pixel voltage means noticeable voltage drop over longer runs; power injection is usually required to hold colour consistency along a long string.
- RGB only (no white channel) and no redundant data line, so a single failed pixel breaks the signal to everything downstream of it.
- The 1920Hz PWM rate is fine for the rated 67fps but leaves limited headroom for very high-speed cinematography beyond that; it is adequate, not exceptional.
Overview
The APA102C is a clocked, individually addressable RGB pixel built on an SMD5050 package with an integrated driver IC. Unlike self-clocked parts, it uses two signal lines, separate DATA and CLOCK, so refresh timing does not depend on tight single-wire pulse widths and the chain can be driven reliably at high data rates. Each pixel runs at 5V with 8-bit-per-channel (24-bit) colour and a 1920Hz PWM rate that is comfortably flicker-free for camera work up to 67fps. ENTTEC is not affiliated with APA Electronic.
Compatible ENTTEC controllers
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.