SM8703AV

NIPPON PRECISION CIRCUITS—8

Sampling Frequency and Output Clock Frequency

The SM8703AV generates several output clocks from the 27 MHz master clock, with frequencies of 384fs

(SO2), 512fs (SO3, SO4) and 768fs (SO5), where fs is the sampling frequency selected by external control

inputs. SO1 outputs 33.8688 MHz clock. The supported sampling frequencies are 44.1 kHz and 48 kHz,

selected by the sampling frequency select pin (FSEL). The generated frequencies are shown in table 1.

Enable/Disable control

3 wire serial interface is available by using MCK(pin4), MLEN(pin5) and MDT(pin23:FSEL common) pins as

serial mode. At the serial control mode, each enable (fixed as "LOW" at disable) of output frequency can be set

to stop unnecessary outputs.

16-bit mode resister (MREG) construction in Figure 4. The name and function of each bit are shown in Table 2

and 3. Set the mode-resister D15-D10 as "011100" in the serial control.

Table 1. Sampling frequency and output clock frequency

FSEL

Sampling

frequency fs

Output clock frequency (MHz)

S O 1

S O 2

SO3, SO4

S O 5

L O W

44.1 kHz

33.8688

16.9344

22.5792

33.8688

HIGH

48 kHz

33.8688

18.4320

24.5760

36.8640

Figure 3. Serial control format

Note: RSV is fixed as LOW .

Figure 4. Mode resister construction

MLEN

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

MCK

FSEL/MDT

0

1

1

1

0

0

RSV

CE5

CE4

CE3

CE2

CE1

RSV

RSV

RSV

MREG

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

RSV