World-Semi WS2811 LED Driver IC

Single-Wire 256-Level Grayscale Three-Channel Constant Current LED Driver

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Key Features:

R, G, B output ports withstand 20V, DIN port withstands 9.5V.
Integrated voltage regulator; for power supplies below 24V, simply connect a resistor in series to the IC VDD pin without the need for an external voltage regulator.
Grayscale adjustment circuit (256 levels of grayscale adjustable).
Built-in signal shaping circuit ensures that any IC receiving a signal will output a waveform-shaped signal, preventing cumulative distortion along the line.
Integrated power-on and power-off reset circuits.
PWM control terminal capable of 256-level adjustment, with a scanning frequency of 2KHz.
Serial interface cascading interface allows for data reception and decoding through a single signal line.
Transmission distance between any two points up to 5 meters without the need for additional circuits.
When the refresh rate is 30 frames per second, the cascading count is no less than 1024 points.
Data transmission speed can reach 800Kbps.
Main Application Areas:

LED full-color letter light strings, LED full-color modules.
LED full-color soft light strips, hard light strips, LED guardrails.
LED point light sources, LED pixel screens, LED special-shaped screens.
Various electronic products, electrical equipment running lights.
Other various LED lighting products.
Product Overview:
The WS2811 is a dedicated circuit for driving and controlling three channels of LEDs. The chip includes an intelligent digital interface, data latching, signal shaping, amplification, and driving circuits. It also features a high-precision internal oscillator and a 20V high-voltage programmable constant current output driver. To reduce power supply ripple, the three channels have a certain delay in conduction, which can reduce circuit ripple during frame refresh. The chip uses a single-wire return-to-zero code communication method. After power-on reset, the DIN terminal accepts data transmitted from the controller. The first 24 bits of data received are extracted by the first chip and sent to the internal data latching register. The remaining data are shaped and amplified by the internal circuit and then forwarded through the DO port to the next cascaded chip. The chip uses automatic shaping and forwarding technology, making the number of cascades only limited by the signal transmission speed requirements.

The internal data latching register generates different duty cycle control signals at the OUTR, OUTG, and OUTB control terminals based on the received 24-bit data. When the DIN terminal input RESET signal is received, all chips synchronize and send the received data to the respective segments. The chip will then receive new data after the signal ends and, after receiving the initial 24-bit data, forward the data through the DO port. Before receiving the RESET code, the OUTR, OUTG, and OUTB pins maintain the original output. After receiving a low-level RESET code for more than 280μs, the chip outputs the received 24-bit PWM data pulse width to the OUTR, OUTG, and OUTB pins.

Available in SOP8 and MSOP8 packages.

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Pin Arrangement and Functions:

OUTR: LED Drive Output - RED (Red) PWM Control Output
OUTG: LED Drive Output - GREEN (Green) PWM Control Output
OUTB: LED Drive Output - BLUE (Blue) PWM Control Output
GND: Ground - Signal and Power Ground
DO: Data Output - Display Data Cascading Output
DIN: Data Input - Display Data Input
NC: No Connection - Leave floating
VDD: Logic Power Supply - IC Power Supply
Maximum Ratings (unless otherwise specified, TA=25℃, VSS=0V):

Logic Supply Voltage (VDD): +3.5 to +5.5 V
R, G, B Output Voltage (VOUT): 20 V
Logic Input Voltage (VI): 2.7V to VDD+0.5V
Operating Temperature (To): -25 to +85 ℃
Storage Temperature (Tstg): -40 to +150 ℃
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Electrical Parameters (unless otherwise specified, TA=-20～+70℃, VDD=4.5～5.5V, VSS=0V):

Low-Level Output Current (IOL): 15.5 to 17.5 mA
Low-Level Output Current (Idout): 10 mA (Vo=0.4V, DOUT)
Input Current (II): ±1 µA (VI=VDD/VSS)
High-Level Input (VIH): 0.7VDD
Low-Level Input (VIL): 0.3 VDD
Hysteresis Voltage (VH): 0.35 V (DIN)
Switching Characteristics (unless otherwise specified, TA=-20～+70℃, VDD=4.5～5.5V, VSS=0V):

Oscillation Frequency (Fosc): 800 KHz
Transmission Delay Time (tPLZ): 300 ns (CL=15pF, DIN→DOUT, RL=10KΩ)
Fall Time (tTHZ): 120 µs (CL=300pF, OUTR/OUTG/OUTB)
Maximum Data Transmission Rate (FMAX): 600 Kbps (Duty Cycle 50%)
Input Capacitance (CI): 15 pF
Data Transmission Timing:

T0H (0 Code, High Level Time): 220ns to 380ns
T1H (1 Code, High Level Time): 580ns to 1us
T0L (0 Code, Low Level Time): 580ns to 1us
T1L (1 Code, Low Level Time): 220ns to 420ns
RES (Frame Unit, Low Level Time): More than 280µs
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Timing Waveform Diagram:

Input Code Type: Connection Method:
Data Transmission Method
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Typical Application Circuits:

Power supply voltage 5V, each channel with a single LED, constant current (16.5mA) output.
Power supply voltage 12V, each channel with three LEDs, constant current (16.5mA) output.
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Package Dimensions and Parameters:

SOP8 Package
MSOP8 Package
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Document Change History:

Version 1.0: New document, 20170524, Shen Jinguo, Yin Hua Ping
Version 1.1: Maximum Ratings, 20171014, Shen Jinguo, Yin Hua Ping
Version 1.2: Switching Characteristics, 20171108, Shen Jinguo, Yin Hua Ping
Version 1.3: Maximum Ratings, Data Transmission Time, Key Features, Product Overview, 2018-2-7, Shen Jinguo, Yin Hua Ping
Note: Initial version number V1.0; each revision approved, the version number is incremented by "0.1"; Status includes: N - New, A - Added, M - Modified, D - Deleted.