®

9

PCM1721

Sampling Frequencies-LRCIN (kHz)

Half of Standard Sampling Freq

16

22.05

24

Standard Sampling Freq

32

44.1

48

Double of Standard Sampling Freq

64

88.2

96

PCM1721’s internal PLL can be programmed for nine

different sampling frequencies (LRCIN), as shown in Table

I. The internal sampling clocks generated by the various

programmed frequencies are shown in Table II. Because of

finite limitations in the PLL’s M and N counters, errors

associated with specific frequencies are shown.

TABLE II. Sampling Frequencies vs Internal System Clock.

FUNCTION

DEFAULT MODE

Input Audio Data Format Selection

Normal Format

Normal Format

Input Audio Data Bit Selection

16/20/24 Bits

16 Bits

Input LRCIN Polarity Selection

Lch/Rch = High/Low

Lch/Rch = High/Low

Lch/Rch = Low/High

De-emphasis Control

OFF

Soft Mute Control

OFF

Attenuation Control

0dB

Lch, Rch Individually

Lch, Rch Individually Fixed

Lch, Rch Common

Infinite Zero Detection Circuit Control

OFF

Operation Enable (OPE)

Enabled

Sample Rate Selection

Internal System Clock Selection

Double Sampling Rate Selection

Standard Sampling Rate—44.1/48/32kHz

Standard Sampling Rate

Double Sampling Rate—88.2/96/32kHz

Half Sampling Rate—22.05/24/16kHz

Sampling Frequency

44.1kHz Group

44.1kHz

48kHz Group

32kHz Group

Analog Output Mode

L, R, Mono, Mute

Stereo

TABLE III. Selectable Functions.

SPECIAL FUNCTIONS

PCM1721 includes several special functions, including digi-

tal attenuation, digital de-emphasis, soft mute, data format

selection and input word resolution. These functions are

controlled using a three-wire interface. MD (pin 8) is used

for the program data, MC (pin 7) is used to clock in the

program data, and ML (pin 6) is used to latch in the program

data. Table III lists the selectable special functions.

HALF OF STANDARD

STANDARD

DOUBLE OF STANDARD

FREQ

SAMPLING FREQUENCY

SAMPLING FREQUENCY

SAMPLING FREQUENCY

ERROR

%

INTERNAL

SYSTEM

CLOCK

(MHz)

16

22.05

24

16

22.05

24

32

44.1

48

32

44.1

48

64

88.2

96

64

88.2

96

4.096

4.0982

0.0537

5.6448

5.64543

0.0112

6.144

6.13634

–0.1247

6.144

6.13634

–0.1247

8.4672

8.46604

–0.0137

9.216

9.21426

–0.0189

8.192

8.18849

–0.0428

11.2896

11.29087

0.0112

12.288

12.2946

0.0537

12.288

12.2946

0.0537

16.934

16.93215

–0.0133

18.432

18.42851

–0.0189

16.384

16.37699

–0.0428

22.5792

22.58174

0.0112

24.576

24.5892

0.0537

24.576

24.5892

0.0537

33.8688

33.8643

–0.0133

36.864

36.85702

–0.0189

TABLE I. Sampling Frequencies.