WS2811B

WS2811B is a dedicated three-channel LED driver control circuit. The chip integrates an intelligent digital interface, data latch, signal reshaping and amplification driver circuit, along with a high-precision internal oscillator and a 40V high-voltage programmable constant-current output driver. To reduce power supply ripple, the OUTR, G, and B channels feature staggered conduction, which reduces circuit ripple during frame refresh. The chip uses a single-wire return-to-zero communication protocol. After power-on reset, the DIN pin receives data transmitted from the controller. The first 24 bits of incoming data are extracted by the first chip and stored in its internal data latch. The remaining data is reshaped and amplified by the internal reshaping circuit, then forwarded via the DO pin to the next cascaded chip. Each chip in the chain extracts 24 bits from the data stream. The chip employs automatic reshaping and forwarding technology, so the number of cascadable chips is not limited by signal degradation — only by signal transmission speed requirements. Based on the received 24-bit data, the internal data latch generates PWM signals with different duty cycles on the OUTR, OUTG, and OUTB control outputs. When a RESET signal is received at the DIN pin, all chips simultaneously transfer the received data to their respective output stages. After the RESET signal ends, the chip begins accepting new data. Once the initial 24 bits are received, data is forwarded through the DO pin. Prior to receiving a RESET code, the OUTR, OUTG, and OUTB pin outputs remain unchanged. Upon receiving a low-level RESET code of 280μs or longer, the chip outputs the received 24-bit PWM data pulse widths to the OUTR, OUTG, and OUTB pins. Available in SOP8 and FSOP8 packages.

Applications

• LED full-color luminous letter light strings, LED full-color modules
• LED full-color flexible/rigid light strips, LED guardrail tubes
• LED point light sources, LED pixel screens, LED custom-shaped screens
• Marquee lighting for various electronic products and electrical equipment
• Other various LED decorative lighting products

Key features

• OUTR, G, B port withstand voltage 40V; DIN, DOUT port withstand voltage 30V
• Built-in voltage regulator; power supplies below 36V only require a series resistor to VDD pin, no external voltage regulator needed
• Grayscale adjustment circuit (256-level adjustable grayscale)
• Signal reshaping circuit — each IC reshapes the waveform before forwarding, preventing cumulative signal distortion along the line
• Built-in power-on reset and power-off reset circuit
• PWM control with 256-level adjustment, scan frequency 4KHz
• Serial cascade interface — data reception and decoding via a single signal line
• Point-to-point transmission distance up to 4 meters without additional circuitry
• Cascade count ≥1024 points at 30 frames/sec refresh rate
• Data transmission speed up to 800Kbps