®

6

PCM1733

1

2

3

16

17

1/fs

L_ch

R_ch

MSB

LSB

18

LRCIN (pin 1)

BCKIN (pin 3)

AUDIO DATA WORD = 18-BIT

DIN (pin 2)

1

2

3

16

17

MSB

LSB

18

2

1

16

17

18

1

2

3

16

17

1/fs

L_ch

R_ch

MSB

LSB

18

LRCIN (pin 1)

BCKIN (pin 3)

AUDIO DATA WORD = 18-BIT

DIN (pin 2)

1

2

3

16

17

MSB

LSB

18

FIGURE 1. “Normal” Data Input Timing.

FIGURE 2. “I2S” Data Input Timing.

LRCKIN

BCKIN

DIN

1.4V

1.4V

1.4V

t

BCH

t

BCL

t

LB

t

BL

t

DS

BCKIN Pulse Cycle Time

BCKIN Pulse Width High

BCKIN Pulse Width Low

BCKIN Rising Edge to LRCIN Edge

LRCIN Edge to BCKIN Rising Edge

DIN Set-up Time

DIN Hold Time

: t

BCY

: t

BCH

: t

BCL

: t

BL

: t

LB

: t

DS

: t

DH

: 100ns (min)

: 50ns (min)

: 50ns (min)

: 30ns (min)

: 30ns (min)

: 30ns (min)

: 30ns (min)

t

DH

t

BCY

FIGURE 3. Audio Data Input Timing.

SYSTEM CLOCK

The system clock for PCM1733 must be either 256fS or

384fS, where fS is the audio sampling frequency (LRCIN),

typically 32kHz, 44.1kHz or 48kHz. The system clock is

used to operate the digital filter and the noise shaper. The

system clock input (SCKI) is at pin 14. Timing conditions

for SCKI are shown in Figure 4.

System Clock Pulse Width High

t

SCKIH

13ns (min)

System Clock Pulse Width Low

tSCKIL

13ns (min)

t

SCKIH

SCKI

t

SCKIL

2.0V

0.8V

FIGURE 4. System Clock Timing Requirements.