TAS5508B_17 Datasheet, PDF (26/104 Pages) Texas Instruments – 8-Channel Digital Audio PWM Processor

TAS5508B
8-Channel Digital Audio PWM Processor
SLES162C – DECEMBER 2005 – REVISED JULY 2009
www.ti.com
Sign
Bit
Integer
Digit 4
(Bits 2¹¹ − 2⁹)
Integer
Digit 1
Integer
Digit 2
Integer
Digit 3
uuuu
uuuu
uuuu
uuuu
Sxxx
xxxx
xxxx
xxxx
Word 1
(Most-
Significant
Word)
Coefficient
Digit 16
Coefficient
Digit 15
Coefficient
Digit 14
Coefficient
Digit 13
Coefficient
Digit 12
Coefficient
Digit 11
Coefficient
Digit 10
Coefficient
Digit 9
Integer
Digit 4
(Bit 2⁸)
Fraction
Digit 6
Integer
Integer
Fraction
Fraction
Fraction
Fraction
Fraction
Digit 5
Digit 6
Digit 1
Digit 2
Digit 3
Digit 4
Digit 5
0
xxxx
xxxx
x. x x x
xxxx
xxxx
xxxx
xxxx
xxxx
Word 2
(Least-
Significant
Word)
Coefficient
Digit 8
Coefficient
Digit 7
Coefficient
Digit 6
Coefficient
Digit 5
Coefficient
Digit 4
Coefficient
Digit 3
Coefficient
Digit 2
Coefficient
Digit 1
u = unused or don’t care bits
Digit = hexadecimal digit
Figure 2-9. Alignment of 25.23 Coefficient in Two 32-Bit I²C Words
M0009-02
2.3.2.3 TAS5508B Audio Processing
The TAS5508B digital audio processing is designed so that noise produced by filter operations is
maintained below the smallest signal amplitude of interest, as shown in Figure 2-10. The TAS5508B
achieves this low noise level by increasing the precision of the signal representation substantially above
the number of bits that are absolutely necessary to represent the input signal.
Similarly, the TAS5508B carries additional precision in the form of overflow bits to permit the value of
intermediate calculations to exceed the input precision without clipping. The TAS5508B advanced digital
audio processor achieves both of these important performance capabilities by using a high-performance
digital audio-processing architecture with a 48-bit data path, 28-bit filter coefficients, and a 76-bit
accumulator.
26
Description
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