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:
Sep. 06, 2016
Filed:
Feb. 10, 2016
Texas Instruments Incorporated, Dallas, TX (US);
Krishnaswamy Nagaraj, Plano, TX (US);
Manish Goel, Plano, TX (US);
Xiao Pu, Plano, TX (US);
Hun-Seok Kim, Ann Arbor, MI (US);
TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US);
Abstract
A direct current ('DC') calibration reference voltage is applied at an input terminal of an N-level sigma-delta analog-to-digital converter ('ADC'). The ADC includes a current-mode DAC (“I-DAC”) operating as a feedback element. A count of logical 1s associated with each of N output levels is taken at outputs of a modulator portion of the ADC during a first mismatch measurement interval. Mismatch measurement logic subsequently transposes pairs of current sources between level selection switch matrices. Doing so causes modulator output error components resulting from mismatches between I-DAC current sources (“delta”) to appear as differential level-specific output counts. The mismatch measurement logic compares the differential counts to determine values of delta. The ADC then factors decimated modulator output counts by values of delta in order to correct for the I-DAC current source mismatch(es).