PN2222 is plenty fast (any transistor is). Not even a consideration until you're in the MHz range.
Can you provide details on what LEDs, resistors, voltages you're dealing with? A schematic of precisely what you're using is what is needed.
PN2222 is plenty fast (any transistor is). Not even a consideration until you're in the MHz range.
Can you provide details on what LEDs, resistors, voltages you're dealing with? A schematic of precisely what you're using is what is needed.