WS2811 LED Driver interface with nRF8122

[HLR]

Hi 

I have RGB LED Strip of 5 numbers and giving out 5V from external power supply 

This LED Strip has WS2811 as LED Driver  (https://cdn-shop.adafruit.com/datasheets/WS2811.pdf)

Din is connected to P0.01 and through PWM coding we will be sending 24 bit of data to rest LED Strip

My doubt is RGB Strip works on 5V and Din from nRF is 3.3V so is it required to make Din to be in 5V  ? though working fine for 10-15 days 

It behaves odd blinking only one or two LEDs

[haakonsh]

You need a level shifter at 3v3 <-> 5v. The WS2811 specifies a minimum voltage for high input is 0.7 * VDD ---> 0.7 * 5V = 3.5V 

This actually means that you can increase the supply voltage of the nRF51 to 3.6V and you should be within the WS2811 spec.