Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsTLV320AIC3120IRHBT

1 2

0 1 2

15 1 2

1 2

N 2 N z N z

H(z)

2 2 D z D z

- -

+ ´ +

- ´ -

0 1

15 1

N N z

H(z)

2 D z

TLV320AIC3120

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SLAS653A –FEBRUARY 2010–REVISED MAY 2012

Table 5-21. Adaptive-Mode Filter-Coefficient Buffer Switching

DAC Page 8, Coefficient

Powered Reg 1, Buffer I

C Writes to Updates

Up Bit D1 in Use

No 0 None Page 8 / register 2 and page 8 / register 3, buffer Page 8 / register 2 and page 8 / register 3, buffer

A A

No 0 None Page 12 / register 2 and page 12 / register 3, Page 12 / register 2 and page 12 / register 3,

buffer B buffer B

Yes 0 Buffer A Page 8 / register 2 and page 8 / register 3, buffer Page 12 / register 2 and page 12 / register 3,

A buffer B

Yes 0 Buffer A Page 12 / register 2 and page 12 / register 3, Page 12 / register 2 and page 12 / register 3,

buffer B buffer B

Yes 1 Buffer B Page 8 / register 2 and page 8 / register 3, buffer Page 8 / register 2 and page 8 / register 3, buffer

A A

Yes 1 Buffer B Page 12 / register 2 and page 12 / register 3, Page 8 / register 2 and page 8 / register 3, buffer

buffer B A

The user-programmable coefficients for the DAC processing blocks are defined on page 8 and page 9 for

buffer A and page 12 and page 13 for buffer B.

The coefficients of these filters are each 16-bit, 2s-complement format, occupying two consecutive 8-bit

registers in the register space. Specifically, the filter coefficients are in 1.15 (one dot 15) format with a

range from –1.0 (0x8000) to 0.999969482421875 (0x7FFF) as shown in Figure 5-12.

5.6.1.3.1 First-Order IIR Section

The IIR is of first order and its transfer function is given by

(4)

The frequency response for the first-order IIR section with default coefficients is flat.

Table 5-22. DAC IIR Filter Coefficients

DAC Coefficient,

Filter Filter Coefficient Default (Reset) Values

Mono Channel

First-order IIR N0 Page 9 / register 2 and page 9 / register 3 0x7FFF (decimal 1.0 – LSB value)

N1 Page 9 / register 4 and page 9 / register 5 0x0000

D1 Page 9 / register 6 and page 9 / register 7 0x0000

5.6.1.3.2 Biquad Section

The transfer function of each of the biquad filters is given by

(5)

Table 5-23. DAC Biquad Filter Coefficients

Filter Coefficient Mono DAC Channel Default (Reset) Values

Biquad A N0 Page 8 / register 2 and page 8 / register 3 0x7FFF (decimal 1.0 – LSB value)