Constant current LED driver min / max current rating explanation
That datasheet is for multiple devices. The LDD-300L is capable of 300mA. The LDD-700L is capable of 700mA. Your device, the LDD-350L, is capable of 350mA. The second page describes the LDD-1000L through LDD-1500L. So the minimum and maximum are for the range of devices, not just a single device.