Hello.
We have not characterized the level shifter for faster speeds; however, adding a 10kΩ pull-up resistor in parallel with the existing pull ups to Lx and Hx on each channel should effectively reduce the time constant by half. If it is still too slow for your application, you might try adding stronger pull-up resistors. (Please note that using stronger pull-ups will increase the board’s power consumption.)
By the way, in our tests, we were able to use a 3.3V signal directly with our WS2812 addressable LEDs. You might try just connecting your controller to the LEDs and see if it works without any level shifting.
I am not sure I understand your other question about PWM signals. What frequency is your PWM signal?
- Jeremy