Worldsemi WS2811S

WS2811S is a three-channel LED driver control circuit. The chip integrates an intelligent digital interface data latch, signal conditioning and amplification driver circuit, along with a high-precision internal oscillator and a programmable constant-current output driver. To reduce power supply ripple, the 3 channels feature a staggered turn-on delay, which helps reduce 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 data are extracted by the first chip and latched into its internal data register; the remaining data is reshaped and amplified by the internal signal conditioning circuit, then forwarded through the DO pin to the next cascaded chip. Each chip in the chain extracts 24 bits from the data stream. The chip employs automatic signal 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 their received data to the respective output stages. After the RESET signal ends, the chip begins accepting new data. Once the initial 24 bits are received, subsequent 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 lasting 280μs or longer, the chip outputs the 24-bit PWM data pulse widths received to the OUTR, OUTG, and OUTB pins.

• R, G, B output ports and DIN port withstand voltage 7V
• Built-in signal reshaping circuit; each IC reshapes the waveform upon reception before forwarding, preventing cumulative waveform distortion along the line
• Built-in power-on reset and power-off reset circuits
• PWM control supports 256-level adjustment with 2KHz scan frequency
• Serial cascade interface — data reception and decoding via a single signal line
• At 30 frames/sec refresh rate, cascade count ≥ 1024 nodes
• Data transmission speed up to 800Kbps

• LED full-color illuminated letter light strings, LED full-color modules
• LED full-color flexible and rigid light strips, LED guardrail tubes
• LED point light sources, chasing light effects for electrical equipment
• Various other LED lighting fixtures and electronic products