Granted Patent
Utility
US 5,057,839 · App. 07/520,521
Integratable switched-capacitor sigma-delta modulator
Inventor:
Rudolf Koch
Patented Case
View Patent ↗
Granted: Oct 15, 1991
Filed: May 7, 1990
Inventor
Rudolf Koch
Assignee (at issue)
Siemens Aktiengesellschaft
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.