Thank you for the additional information. Since your application is a clock and will likely need to run nonstop for very long periods of time and need to stay very constant, a brushed DC motor is probably not the best solution. You might consider something like a stepper motor instead. You could use one of our current limiting stepper motor drivers, which accept a two-pin step and direction interface. Since it sounds like you are not likely to need to change directions, this could be reduced to just a step signals by tying the DIR pin high or low. This step signal could be sent from a separate microcontroller like an Arduino or some other device that can output a square-wave with the frequency you need.
By the way, just to clarify for anyone else reading this, while a PC is necessary to configure the jrk controllers, the jrk does not need to be connected via USB to a computer to function; it can be controlled from an analog voltage input, TTL serial commands, or a hobby RC signal as well.