I'm wanting to drive a NeoPixel from a CMOS device. The power for the neopixel is a 4v LiPo battery and will fall from around 3.9v to 3v before it cuts off. I have a few PN2222 NPN transistors, I'm not sure what kind of circuit I should be building out of them. The neopixel needs around 0.4us timing.
The CMOS device will have a step up/down regulator. It's output will be a steady 3.3v. I will be powering the neopixels from the battery directly (3.9-3v is in it's operating range). I need to ensure the signal the CMOS device is sending to the neopixels matches the neopixel's input voltage.