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:
Feb. 07, 1995
Filed:
Feb. 22, 1993
Christopher W Mangelsdorf, Reading, MA (US);
Analog Devices, Incorporated, Norwood, MA (US);
Abstract
An analog-to-digital converter (ADC) having three cascaded A/D stages of the 'flash' type. In the first stage, the analog signal is compared with a set of threshold reference voltages so as to develop a set of most-significant bits and to produce two analog residue signals: (1) a normal residue corresponding to the difference between the analog input and the reference voltage next below the analog input, and (2) a second residue corresponding to the difference between the analog input and the reference voltage next above the analog signal level. These two residue signals are amplified and directed to the second A/D stage. The sum of the residue signals equals one LSB of the first A/D stage, so that the two residues supply to the second stage information about the quantization error of the previous stage as well as the quantization step size to be used to define full-scale at the second stage. The second A/D stage develops a set of less-significant bits and two more residue signals for the third A/D stage. The second stage further includes a capacitor network arranged to effectively double the operating range of that stage to accommodate error correction.