Hello.
Instead of using a logic level shifter, you could also just use appropriate voltage dividers on the encoder outputs, but if you decide to use the logic level shifter, that would be fast enough to handle the encoder signals.
By the way, the maximum frequency should be about 2.7kHz (well within the limits of what the level shifter can handle). In case you are interested, here is how I calculated that:
Max motor speed = speed • gear ratio = 330rpm • 30 = 9900rpm = 165rps
encoder pulses per rotation per channel = 64cpr / 2 channels / 2 counts per pulse (high and low) = 16 pulses per rotation
frequency = Max motor speed • encoder pulses per rotation per channel = 165rps • 16 pulses per rotation = 2640Hz = 2.64kHz
(I suspect your error might have been using speed in rpm rather than rps in the last equation.)
- Patrick