WS2811AF

WS2811AF is an IC optimized specifically for 12~24V applications based on the WS2811, utilizing the latest patented technology. It features strong interference immunity with highly optimized EMC/EMI performance, low radiated emissions, and can easily pass EMC/EMI test standards. The IC is highly integrated internally, requiring no external components for 12V applications (no resistors or capacitors needed, direct 12V power supply supported), resulting in a simpler end-product design and more convenient production. WS2811AF remains a dedicated three-channel LED driver control circuit. The chip internally integrates an intelligent digital interface, data latch, signal reshaping and amplification driver circuit, along with a high-precision internal oscillator and a 20V high-voltage programmable constant-current output driver. Additionally, to reduce power supply ripple, the 3 channels feature a staggered turn-on delay function, which reduces circuit ripple during frame refresh. The chip uses a single-wire return-to-zero (NRZ) 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 the internal data register; the remaining data is reshaped and amplified by the internal signal reshaping circuit, then forwarded and output to the next cascaded chip via the DO pin. 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 cascaded 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, the data is forwarded via the DO pin. Before receiving a RESET code, the output states of OUTR, OUTG, and OUTB remain unchanged. Upon receiving a low-level RESET code of 200μs or longer, the chip outputs the 24-bit PWM pulse width data just received to the OUTR, OUTG, and OUTB pins.

Applications

• LED full-color luminous letter light strings, LED full-color light strips, COB light strips.
• LED point light sources.

Key features

• Latest patented technology; strong anti-interference, highly optimized EMC/EMI, low radiation.
• Highly integrated IC; no peripheral components required for 12V applications; high cost-effectiveness.
• R, G, B output ports and DIN/DOUT ports withstand voltage ≥20V; VDD port withstand voltage ≥15V.
• Built-in signal reshaping circuit; each pixel reshapes the received signal before output, preventing cumulative waveform distortion along the line.
• Built-in power-on reset and power-down reset circuits.
• PWM control supports 256-level adjustment; R, G, B output port refresh rate up to 3.3KHz/s.
• Serial cascade interface; data reception and decoding via a single signal line.
• No additional circuitry required for transmission distances up to 3 meters between any two points.
• At a refresh rate of 30 frames/sec, cascade count no less than 1024 pixels.
• Data transmission speed up to 800Kbps.
• Available in a unique white SOP8 package.