REV. 0

AD1833A

–11–

DAC Word Width

The AD1833A will accept input data in three separate word-

lengths—16 bits, 20 bits, and 24 bits. The word length may be

selected by writing to Control Bits 4 and 3 in DAC Control

Register 1 (see Table V).

Table V. Word Length Settings

Bit 4

Bit 3

Word Length

00

24 Bits

01

20 Bits

10

16 Bits

11

Reserved

Power-Down Control

The AD1833A can be powered down by writing to Control Bit 2

in DAC Control Register 1 (see Table VI).

Table VI. Power-Down Control

Bit 2

Power-Down Setting

0Normal Operation

1

Power-Down Mode

Interpolator Mode

The AD1833A’s DAC interpolators can be operated in one of

three modes—8 , 4

, or 2 — then correspond to 48 kHz, 96 kHz,

and 192 kHz modes, respectively (for IMCLK = 24.576 MHz). The

interpolator mode may be selected by writing to Control Bits 1

and 0 in DAC Control Register 1 (see Table VII).

Table VII. Interpolator Mode Settings

Bit 1

Bit 0

Interpolator Mode

00

8x (48 kHz)

*

01

2x (192 kHz)

*

10

4x (96 kHz)

*

11

Reserved

*For IMCLK = 24.576 MHz.

DAC CONTROL REGISTER 1

De-emphasis

The AD1833A has a built-in de-emphasis filter that can be used

to decode CDs that have been encoded with the standard

Redbook 50

ms/15 ms emphasis response curve. Three curves are

available, one each for 32 kHz, 44.1 kHz, and 48 kHz sampling

rates. The filters may be selected by writing to Control Bits 9

and 8 in DAC Control Register 1 (see Table III).

Table III. De-emphasis Settings

Bit 9

Bit 8

De-emphasis

00

Disabled

01

44.1 kHz

10

32 kHz

11

48 kHz

Data Serial Interface Mode

The AD1833A’s serial data interface is designed to accept data

in a wide range of popular formats including I

(RJ), left-justified (LJ), and flexible DSP modes. The L/RCLK

pin acts as the word clock (or frame sync) to indicate sample

interval boundaries. The BCLK defines the serial data rate

while the data is input on the SDIN1–SDIN3 pins. The serial

mode settings may be selected by writing to Control Bits 7

through 5 in the DAC Control Register 1 (see Table IV).

Table IV. Data Serial Interface Mode Settings

Bit 7

Bit 6

Bit 5

Serial Mode

0

00I

0

01Right Justify

0

10

DSP

0

11Left Justify

1

00Packed Mode 1 (256)

1

01Packed Mode 2 (128)

1

10

TDM Mode

1

11Reserved

Table II. DAC Control Register 1

Function

Data-Word

Power-Down

Interpolator

Address

Reserved

1

De-emphasis

Serial Mode

Width

RESET

Mode

15–12

11

10

9–8

7–5

4–3

2

1–0

0000

0

0

00 = None

000 = I

00 = 24 Bits

0 = Normal

00 = 8

(48 kHz)

2

01 = 44.1 kHz

001 = RJ

01 = 20 Bits

1 = PWRDWN

01 = 2

(192 kHz)

2

10 = 32.0 kHz

010 = DSP

10 = 16 Bits

10 = 4

(96 kHz)

2

11 = 48.0 kHz

011 = LJ

11 = Reserved

11 = Reserved

100 = Pack Mode 1 (256)

101 = Pack Mode 2 (128)

110 = TDM Mode

111 = Reserved

NOTES