WS2811

1-wire RGB · WorldSemi · ws281x

Channels
RGB
Bits / channel
8
Supply
5–24 V
PWM
—
Backup data
no
Packages
0

The ancestor of the family: a standalone three-channel constant-current driver rather than an LED. Included because “WS2811” is what a lot of 12 V strip is sold as, and because the WS2812 is essentially this IC bonded into a 5050 package with the LEDs.

Refresh & flicker

An external driver IC, not an integrated LED. It drives three channels of discrete LEDs, which is why it appears in 12 V strip modules of three LEDs per IC rather than in a single package.

Timing

WS2811 bit timingWS2811 bit timing: a zero bit is 500 nanoseconds high then 2000 low; a one bit is 1200 high then 1300 low; reset 280 microseconds low1 · Bit encoding, to scaleDINhighlowbit 0 period 2500 nsbit 1 period 2500 nsT0H 500 nsT1H 1200 nsT0L 2000 nsT1L 1300 ns"0" bit"1" bit0500100015002000250030003500400045005000time, ns2 · One frame: 24 bits, most-significant bit firstDIN170110010007100110101700101100bitG · 8 bitsR · 8 bitsB · 8 bitsWire order GRB · frame = 24 × ~2500 ns ≈ 60 µs · example data, first bits 1 0 1 …3 · RESET / latchlast bits of frame 1first bits of frame 2LEDs latch the data they receivedRESET: DIN low ≥ 280 µs (not to scale)4 · Cascade: each DOUT feeds the next DINMCULED 1DINDOUTLED 2DINDOUTLED NDINDOUTLED 1 keeps the first 24 bits, re-shapes the signal and sends the rest out on DOUT;LED 2 keeps the next 24, and so on. The last LED's DOUT is left unconnected.
T0H 500 / T0L 2000 · T1H 1200 / T1L 1300 ns · period 2500 ns · reset 280 µs source: fastled (driver-tuned, not the datasheet)
SourceT0HT0LT1HT1LPeriodRateReset±
fastled ↗ 500 ns 2000 ns 1200 ns 1300 ns 2500 ns 400 kHz 280 µs —
FastLED also ships an 800 kHz WS2811 variant (250/350/650). Later WS2811 silicon is commonly 800 kHz; early parts are 400 kHz. Which one you have is a coin toss without testing.

Clones & compatibility

“Compatible” is never stated bare here — each relationship carries how strong the claim is, and what bites if you assume too much.

  • electrically similar of this UCS1903

    Both are external three-channel drivers used in 12 V strip at a similar data rate, but the bit timings differ and they are not interchangeable without reconfiguring the driver.

Library support

FastLED
WS2811 ↗
Adafruit_NeoPixel
NEO_GRB + NEO_KHZ400
WLED
WS281x

Ubiquitous. Every library supports it.

Parts using this protocol

No package is catalogued for this protocol yet — it is seeded for family completeness, or it is a driver IC that drives external LEDs rather than shipping as an integrated package.

Dating evidence

Evidence, not a release date. A library commit proves the part existed by that date and says nothing about how long before.

  • 2012-10-15 first library support FastLED — first commit introducing WS2811 ↗ day
  • 2018-11-24 first library support WLED — first commit introducing WS2811 ↗ day