The DVD Burner Optiarc AD-5630A was first noticed in Apple laptops in September 2007. The Optiarc AD5633 burner adds support for LabelFlash but both drives share the same hardware and only differ in firmware. However you should not try to simply flash an Optiarc 5633 firmware on an Optiarc 5630 drive or vice versa. This will NOT work.
Click here for detailed specifications of the Optiarc AD5630A.
The following firmwares are available for download here:
Overview on the used writing strategies