According the the datasheet, the absolute max is 60V but that would include back emf. The question would be is it possible, sure...did you, maybe. Do you have a oscilloscope? If so, put a load resistor of the value that emulates you coil resistance for each phase of the appropriate wattage. Put it in full step mode and see if you have good square waves swing from ground to your 48V. If you don't then try some different step modes and see if that makes any difference.