The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1991
Filed:
Dec. 27, 1989
Pham N Tung, Paris, FR;
Thomson Composants Microondes, Puteaux, FR;
Abstract
In a cascaded analog-digital converter, a first ADC determines the most significant bits. To determine the least significant bits, in a second ADC, it is necessary to assess the difference between the input analog signal V.sub.E and its already digitized part, reconverted into analog form. The subtractor/amplifier receives, firstly, the input signal V.sub.E which is converted into a current i.sub.E and, secondly, the most significant bits on a digital-analog converter. This constitutes a source, capable of being modulated, which gives a current i.sub.c. Two parallel-mounted transistors differentiate between the current i.sub.c of the source capable of being modulated and the current i.sub.E corresponding to the input signal V.sub.E, and amplify it. The disclosure is applicable to cascaded ADCs.