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:
Dec. 27, 2011
Filed:
Jun. 04, 2009
Steven E Turner, Nashua, NH (US);
Richard B Elder, Jr., Bedford, NH (US);
Steven E Turner, Nashua, NH (US);
Richard B Elder, Jr., Bedford, NH (US);
BAE Systems Information and Electronic Systems Integration Inc., Nashua, NH (US);
Abstract
A digital to analog converter (DAC) method and apparatus employs a multiplying-adding DAC, eliminating digital adder circuitry. Examples are given for multiplying a 3-bit binary number by a 2-bit binary number; however, there are no limitations to the bit-widths of the numbers to be multiplied. The multiplying-adding DAC method can be scaled up or down in bit-width by feeding the DAC with partial sums and adjusting the DAC weights accordingly. An analog to digital converter (ADC) can be placed after the DAC to generate a digital output. By multiplexing preset digital data into the DAC core for return to zero (RTZ), a true zero that is the midpoint of the DAC output range is achieved. It does not return to a rail for single-ended outputs. RTZ in DAC circuits doubles the null frequency of sin(x)/x roll-off inherent in DACs and also helps reduce switching glitches in the DAC output.