Coded data generation or conversion – Analog to or from digital conversion – Differential encoder and/or decoder
Reexamination Certificate
2007-05-22
2007-05-22
Nguyen, Khai M. (Department: 2819)
Coded data generation or conversion
Analog to or from digital conversion
Differential encoder and/or decoder
C341S131000, C341S144000
Reexamination Certificate
active
11216292
ABSTRACT:
A sigma delta digital-to-analog (D/A) converter system (10) includes a summing device (35) at an input of a D/A converter (30), and a low frequency low amplitude wave signal (31) injected at an input of the summing device that remains unfiltered and is used to suppress spurious tone artifacts. The D/A converter system can further include an amplitude control and a frequency control for selectively adjusting the frequency and the amplitude of the low frequency low amplitude wave signal being injected. Note, the low frequency low amplitude repeating wave signal generator can take the form of a digital signal processor (DSP) (37) having the appropriate software to generate such signals.
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Ballantyne Wayne W.
Behboodian Ali
Frangopol Radu C.
Patterson Audley F.
Motorola Inc.
Nguyen Khai M.
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