WS2811 Datasheet – Constant current LED drive IC

This post describes for the semiconductor WS2811 Datasheet.

Part Number : WS2811.

Package : DIP 8 Pin, SOP 8 Pin.

Function : 256 Gray level 3 channal Constant current LED drive IC.

Manufacturer : WorldSemi ( ).


WS2811 Datasheet

Description :

The WS2811 is 3 output channels special for LED driver circuit. It internal include intelligent digital port data latch and signal reshaping amplification drive circuit.Also include a precision internal oscillator and a 12V voltage programmable constant current output drive. In the purpose of reduce power supply ripple, the 3 output channels designed to delay turn-on function.

IC use single NZR communication mode.After the chip power-on reset, the DIN port receivedata from controller, the first IC collect initial 24bit data then sent to the internal data latch, theother data which reshaping by the internal signal reshaping amplification circuit sent to the next cascade IC through the DO port. After transmission for each chip,the signal to reduce 24bit. IC adopt auto reshaping transmit technology, making the chip cascade number is not limited the signal transmission, only depend on the speed of signal transmission.



WS2811 pdf schematic


1. Output port compression 12V.
2. Built in stabilivolt, Only add a resistance to IC VDD feet when under 24V power supply.
3. Gray level 256 can be adjusted and scan frequency not less than 400Hz/s.
4. Built in signal reshaping circuit,after wave reshaping to the next driver, ensure wave-form distortion not accumulate.



1. LED decorative lighting.

2. Indoor / outdoor LED video or irregular screen

Reference Site :

How to control WS2811 RGB LED with Arduino –

WS2811 Dataheet

PT4115 Datasheet – 30V, 1.2A Step-down LED Driver

Part Number : PT4115

Function : 30V, 1.2A Step-down  High Brightness LED Driver with 5000:1 Dimming

Package : SOT89-5 , ESOP8 Pin Type

Manufacturers : PowTech

See the preview image and the PT4115 Datasheet file for more information.

Image :

PT4115 image
Description :

The PT4115 is a continuous conduction mode inductive step-down converter, designed for driving single or multiple series connected LED efficiently from a voltage source higher than the total LED chain voltage.
The device operates from an input supply between 6V and 30V and provides an externally adjustable output current of up to 1.2A. Depending upon the supply voltage and external components, the PT4115 can provide more than 30 watts of output power. The PT4115 includes the power switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current, and a dedicated DIM input accepts either a DC voltage or a wide range of pulsed dimming. Applying a voltage of 0.3V or lower to the DIM pin turns the output off and switches the device into a low current standby state.

PT4115 Pinout

PT4115 pinout


1. Simple low parts count
2. Wide input voltage range: 6V to 30V
3. Up to 1.2A output current
4. Single pin on/off and brightness control  using DC voltage or PWM
5. Up to 1MHz switching frequency
6. Typical 5% output current accuracy
7. Inherent open-circuit LED protection
8. High efficiency (up to 97%)
9. High-Side Current Sense
10. Hysteretic Control: No Compensation
11. Adjustable Constant LED Current
12. ESOP8 package for large output power application
13. RoHS compliant


PT4115 circuit

Other data sheets within the file : PT4115B89E, PT4115B89E-B, PT4115BSOH, PT4115BSOH-B

PT4115 Datasheet PDF Download