PCM1802

SLES023B – DECEMBER 2001 – REVISED MARCH 2002

13

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PRINCIPLES OF OPERATION

system clock

frequency. The system clock must be supplied on SCKI (pin 15).

The PCM1802 has a system clock detection circuit which automatically senses if the system clock is operating

delta-sigma modulator and the digital filter.

Table 1 shows the relationship of typical sampling frequencies and system clock frequencies, and Figure 22

shows system clock timing.

Table 1. Sampling Frequency and System Clock Frequency

SAMPLING RATE

FREQUENCY

SYSTEM CLOCK FREQUENCY (MHz)

FREQUENCY

(kHz)

256 fS

384 fS

512 fS

768 fS

32

8.192

12.288

16.384

24.576

44.1

11.2896

16.9344

22.5792

33.8688

48

12.288

18.432

24.576

36.864

64

16.384

24.576

32.768

49.152

88.2

22.5792

33.8688

45.1584

—

96

24.576

36.864

49.152

—

SCKI

0.8 V

SCKI

2.0 V

tSCKL

tSCKH

PARAMETER

MIN

MAX

UNIT

tSCKH

System clock pulse width, high

7

ns

tSCKL

System clock pulse width, low

7

ns

Figure 22. System Clock Timing