Coded data generation or conversion – Digital code to digital code converters – To or from particular bit symbol
Reexamination Certificate
2008-05-27
2009-12-01
Mai, Lam T (Department: 2819)
Coded data generation or conversion
Digital code to digital code converters
To or from particular bit symbol
C375S238000
Reexamination Certificate
active
07626519
ABSTRACT:
Digital audio circuitry including modulation circuitry (35; 135) for generating a pulse-width modulated (PWM) signal from processed pulse-code modulated (PCM) audio signals. The modulation circuitry includes a duration quantizer function (32) that generates a sequence of duration values d(k) from received PCM samples, quantized to integer multiples of periods of a master PWM clock (CLKpwm). The duration quantizer function also produces a feedback PCM value x(k) from each quantized duration value d(k) that is applied to a loop filter (36), the output of which modifies the received PCM sample stream to suppress quantization noise. Transient effects caused by modulation or abrupt changes in the desired PWM period are suppressed by digitally filtering (34; 134) the PWM period sample stream.
REFERENCES:
patent: 6657566 (2003-12-01), Risbo et al.
patent: 7224728 (2007-05-01), Komamura
patent: 7308027 (2007-12-01), Gaboriau et al.
patent: 7317758 (2008-01-01), Alrutz et al.
patent: 7492217 (2009-02-01), Hansen et al.
patent: 2004/0184621 (2004-09-01), Andersen et al.
patent: 2005/0110667 (2005-05-01), Borisavljevic
patent: 2005/0122241 (2005-06-01), Magrath
patent: 2005/0254573 (2005-11-01), Midya et al.
Midya, “Generation of Variable Frequency Digital PWM”, Paper No. 7227, Presented at the 123rd Convention of the Audio Engineering Society (Oct. 5-8, 2007).
“Generation of Variable Frequency Digital PWM,” Audio Engineering Society Convention Paper 7227, presented at the 123rd Convention, Oct. 5-7, 2007, New York, US, pp. 1-10 (Pallab Midya).
Brady III Wade J.
Mai Lam T
Patti John J.
Telecky , Jr. Frederick J.
Texas Instruments Incorporated
LandOfFree
Pulse-width modulation of pulse-code modulated signals at... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pulse-width modulation of pulse-code modulated signals at..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pulse-width modulation of pulse-code modulated signals at... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4061780