Coded data generation or conversion – Analog to or from digital conversion – Digital to analog conversion
Reexamination Certificate
2009-06-04
2011-12-27
Nguyen, Linh (Department: 2819)
Coded data generation or conversion
Analog to or from digital conversion
Digital to analog conversion
C341S144000, C341S145000
Reexamination Certificate
active
08085178
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.
REFERENCES:
patent: 5684482 (1997-11-01), Galton
patent: 6281825 (2001-08-01), Lee
patent: 6414615 (2002-07-01), Cheng
patent: 6812878 (2004-11-01), Jewett et al.
patent: 6977602 (2005-12-01), Ostrem et al.
patent: 7042379 (2006-05-01), Choe
patent: 7187310 (2007-03-01), El-Sankary et al.
patent: 7227477 (2007-06-01), Ye
patent: 7312737 (2007-12-01), Jungerman et al.
patent: 7501969 (2009-03-01), Schoner
patent: 7545925 (2009-06-01), Williams
patent: 7956785 (2011-06-01), Baek et al.
patent: 8022850 (2011-09-01), Newman
patent: 2006/0227025 (2006-10-01), El-Sankary et al.
patent: 2009/0195425 (2009-08-01), Eloranta et al.
Choe, Myung-Jun et al., “A 1.6-GS/s 12-Bit Return-To-Zero GaAs RF DAC for Multiple Nyquist Operation”, IEEE Journal of Solid-State Circuits, Dec. 2005, 13 pages, vol. 40, No. 12.
Elder, Jr. Richard B
Turner Steven E
BAE Systems Information and Electronic Systems Integration Inc.
Nguyen Linh
Rardin David A.
Vern Maine & Associates
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