Quote Originally Posted by 51dueller View Post
The L293D can only handle up to a 5 khz signal where as the circuit above can go 31.2 khz.
How fast will your input signal be?
The ECCP of the pic16f684 using pwm can microstep the motor providing an extremely smooth and accurate rotation. Microstepping the motors I have will rotate 0.083 degrees a step.
Microsteping is a term referring to modulating the current to each coil of a step motor in an effort to gain step resulotion. That is all microstepping describes. The circuit above appears to microstep to 1/8 step. It may be 1/16, but I don't think so. So what does 1/8 step mean? a full step is the amount of movement when 1 coil is energized. So 1/8 step is just that: full step/8. Taking the statement from the datasheet as you have "Microstepping the motors will rotate 0.083 degrees a step". You left out a very important part of that statement. The data sheet says microstepping at a rate of 12 steps per degree! Full step for your motor is .5 deg per step. So the microstepping they refer to is 1/6 step. All this just to say Using above circuit at full microstep mode, will really be .0625 deg per step.

If you know of a single chip driver that can equal the resolution of the above circuit, I'm very much interested.
I agree with Alain above. But before I did that, without telling anyone, I would try to direct drive it some how in full or half step .Afterall its only 22mA. But I also don't mind leting the magic smoke out