UCS1903 Pixel Protocol
Manufacturer: Shenzhen UCS
UCS1903 is a single-wire, self-clocking RGB pixel driver with an integrated 8-bit-per-channel controller, common on legacy and budget LED strings.
Specifications
| Clock Type | Data-Only |
| Color Resolution | 8 Bits |
| Physical Package | SOP8 |
| RGB | Yes |
| RGBW | No |
| Output Pixel Voltage | 5 - 12V |
| PWM Rate | 400Hz |
| Suitable Camera | Flickering may be visible |
| Redundant Data Line | No |
Strengths
- Single-wire signalling: only one data conductor is needed alongside power and ground, with no separate clock line to route, making cabling simpler and cheaper than two-wire clocked chips such as APA102 or P9813.
- Faster, more stable timing than the earliest WS2811-class parts, supporting reliable daisy-chained runs while carrying full 24-bit RGB (8 bits, or 256 levels, per channel).
- Wide 5 to 12V pixel-voltage support: the higher end of the range helps reduce voltage drop over longer strings compared with 5V-only parts.
Limitations
- The 400Hz PWM refresh is low, and the spec row lists this chip as likely to show visible flicker on camera: expect visible flicker or rolling banding on video, so avoid it for on-camera, film, or broadcast use and treat it as a live-viewing / architectural part only.
- No redundant (backup) data line: a single failed pixel or broken data joint blacks out the entire downstream chain, so plan injection points and consider reliability-critical runs carefully. Being single-wire and self-clocking, timing is also strict, and signal integrity over long or electrically noisy cable runs can need reclocking or buffering (for example via PLINK injectors).
- Colour depth is 8 bits per channel (256 steps), so very slow fades and low-level dimming can show stepping compared with higher-bit-depth drivers; it is RGB only, with no dedicated white (RGBW) channel.
Overview
The UCS1903 is a data-only, single-wire addressable RGB pixel driver commonly attributed to Shenzhen UCS. One self-clocking data line is daisy-chained from pixel to pixel, with each SOP8 device latching its own 24-bit slice (8 bits per channel) before forwarding the remaining data down the chain. It operates across a 5 to 12V pixel-supply range and refreshes its PWM output at roughly 400Hz, which is low enough to show banding or flicker on camera, so it suits architectural and static decorative installs rather than broadcast work. ENTTEC is not affiliated with Shenzhen UCS.
Compatible ENTTEC controllers
Sku: 71521
Sku: 73539
Sku: 70067
Sku: 70068
Sku: 73-545
Sku: 73924
ENTTEC has been engineering lighting control in Australia since 1999, and shipping LED pixel controllers since the original Pixelator in 2014.