Can I use I²C level shifters to power digital LED strips, more specifically, WS2812B strips?
I can only find I²C level shifters, are they ok?
Can I use I²C level shifters to drive WS2812B Digital LED strips?
Your question could do to be clarified somewhat.
I assume that you want to interface a 3.3V MCU controller to the 5V required for the WS2812 LED strips data input.
The readily available level shifters use a single active device and are very suitable for your task.
This is the typical schematic for the level shifter:
These will work well for your application.
Connect LV to 3.3V, and drive the TX2_LV from your 3.3V MCU.
Connect HV to 5V, and drive the WS2812B data pin from TX2_HV.
The cost of these level shifter (10 for less than $3) makes them ideal for the hobbyist. One level shifter board will drive 4 individual LED strips.
Note: After active discussion in the comments I'll add this:
From the comments these two links provide useful commentary (particularly the comments):
I2C is bidirectional, you don't need bidirectional level shifters for the WS2812B which uses a single-wire asynchronous protocol.
For example, 74LVCH1T45 is a suitable unidirectional level shifter that will work with a wide range of input and output voltages.
Edit: Bidirectional level shifters with discrete MOSFETs that use 10K pullups will likely cause problems- the tolerance is +/-150ns on the timing. A time constant of 150ns with 10K is the equivalent of only a few inches of wire. It will probably work with a very short wire, but become erratic or stop working with longer lengths. If you mount the level shifter right beside the first WS2812B in the chain it may be usable.
Timing requirements from the datasheet:
Here is a simulation of the BSS138 circuit. The red represents the minimum the WS2812B requires (timing and Vih). With a load of only 5pF and all voltages at nominal the timing is barely meeting spec typically. In any real setup this will be guaranteed to be out of spec, and if it works it will be by luck.
When estimating we cannot ignore the input capacitance of the WS2812B nor the significant capacitance of the BSS138 (although it's one of the lowest capacitance types that is suitable).
Of course you can, most likely, reduce the output 10K resistor or parallel it with another resistor and get it to work reliably enough for a hobby project.