Method and system for converting digital samples to an analog signal

• US 20060119497A1
• Filed: 01/31/2006
• Published: 06/08/2006
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Klingler, Keith LaRell, Miller, Kevin Lee, Schoner, Brian Francis
• Granted Patent: US 7,145,488 B2
• Time in Patent Office: Days
• US Class Current: 341/144
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/10037 A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof
• CPC Class Codes: H03M 1/66 Digital/analogue converters H03M1/001 – H03M1/10 take precedence

Abstract

Provided is a system and method for converting digital data audio data audio data that has a predetermined input sample rate, into an analog data signal. A system includes a digital to analog converter (DAC) including a digital processing portion configured to receive as an input the digital audio data and timing information, the timing information being representative of a time base of the input sample rate. The digital processing portion is similarly configured to digitally process the digital audio data and the timing information to produce serialized output data. The DAC also includes an analog processing portion configured to convert serialized data to an analog format. The digital processing portion operates in accordance with at least one clock having a corresponding clock rate wherein the corresponding clock rate is unrelated to the input sample rate.

Claims

1. A digital to analog converter (DAC) configured to convert input digital data having a predetermined input sample rate to analog data, comprising:

a digital portion configured to (i) receive the digital data and timing information representative of a time base of the input sample rate and (ii) digitally process the digital data and the system timing data to produce serialized output data; and

an analog portion configured to convert the serialized data to an analog format;

wherein the digital portion operates in accordance with at least one system clock having a corresponding system clock rate independent of the input sample rate.

2. The DAC of claim 1, wherein the digital portion includes a rate manager and a rate converter.

3. The DAC of claim 2, wherein the rate converter is asynchronous.

4. The DAC of claim 2, wherein the rate manager receives the input sample rate data in accordance with the clock and produces an input sample rate value therefrom.

5. The DAC of claim 4, wherein the value correlates the input sample rate with a desired output sample rate.

6. The DAC of claim 5, wherein the value is a fractional value having ranges from −

2¹⁷ to 2¹⁷.

7. A method for converting digital data having a predetermined input sample rate to analog samples in a digital to analog converter (DAC), the method comprising:

receiving timing information representative of a time base of input data having a predetermined input sample rate;

producing an input sample rate value based upon the received timing information, the input sample rate value being representative of the predetermined input sample rate and a desirable output sample rate; and

rate converting the input data based upon a system clock to produce output samples at in accordance with the input sample rate value, the output samples being output at the desirable output sample rate;

wherein the input sample rate is independent of the system clock.

8. The method of claim 7, wherein the rate converting is asynchronous.

9. The method of claim 8, wherein the input sample rate value is a fractional value having ranges from −

2¹⁷ to 2¹⁷.

10. The DAC of claim 9, wherein the fractional value is computed each period of the system clock.