Granted Patent
Utility
US 6,563,377 · App. 09/973,360
Class D switching audio amplifier
Inventor:
Joel Butler
Patented Case
View Patent ↗
Granted: May 13, 2003
Filed: Oct 9, 2001
Inventor
Joel Butler
Assignee (at issue)
Evenstar, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.