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. 01, 1998
Filed:
Feb. 05, 1997
Stanford University, Palo Alto, CA (US);
Abstract
A method for simultaneously performing bit serial analog to digital conversion (ADC) for a potentially very large number of signals is described. The method is ideally suited for performing on chip ADC in area image sensors. In one embodiment, to achieve N-bit precision, the method employs a one-bit comparator per channel (or set of multiplexed channels) and an N-bit DAC. To achieve N bits of precision, 2.sup.N -1 comparisons are sequentially performed. Each comparison is performed by first setting the DAC output to the desired value and then simultaneously comparing each of the pixel values to that value. If a pixel value is greater than the DAC output value, its comparator outputs a one, otherwise it outputs a zero. By appropriately choosing the sequence of comparison values, the pixel values are sequentially generated. In another embodiment, the DAC is omitted and a continuous ramp signal is generated for comparison with the analog input.