M1725

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

9 of 10

www.unisonic.com.tw

QW-R502-427.A

FUNCTIONAL DESCRIPTION

SYSTEM CLOCK

32kHz, 44.1kHz or 48kHz. The system clock is used to operate the digital filter and the noise shaper. Timing

conditions for SCKI are shown in Figure4.

M1725

The system clock should be synchronized with LRCIN,but M1725 can compensate for phase differences. If the

phase difference between LRCIN and system clock is greater than ±6 bit clocks (BCKIN), the synchronization is

performed automatically. The analog outputs are forced to a bipolar zero state (VCC/2) during the synchronization

function. The typical system clock frequency inputs vs sampling rate for the M1725 is shown below.

SYSTEM CLOCK FREQUENCY(MHz)

SAMPLING RATE(LRCIN)(kHz)

32

8.192

12.288

44.1

11.2896

16.934

48

12.288

18.432

INPUT DATA FORMAT

M1725

can accept input data in either normal (MSB-first, right-justified) or I

voltage level on FORMAT-pin.

FORMAT

INPUT DATA FORMAT SELECTED

Low

Normal Format (MSB-first, right-justified)

High

I2S Format (Philips serial data protocol)

DE-EMPHASIS CONTROL

DM-pin enables M1725’s de-emphasis function. De-emphasis operates only at 44.1kHz.

DM

DE-EMPHASIS FUNCTION SELECTED

Low

De-emphasis ON (44.1kHz)

High

De-emphasis OFF

RESET

M1725

includes an internal power-on reset circuit. The power-on reset initializes and has an initialization period

the analog outputs are forced to VCC/2.