AV2636

Product Datasheet

OPERATING MODE

The AV2636 can operate at two modes. They are auto-detect mode and programmable mode. The

‘MODE’ pin status (High/Low) determines which mode the device will be operated. If MODE = Low (pull to

GND or not connected using internal pull down), the device will be operated at auto-detect mode. If

MODE = High (pull to VDD), the device will be operated at programmable mode. The basic functions of

the two modes are described as follows:

•

Auto-detect mode: The relation between sample rate and master clock frequency is auto detected.

De-emphasis and serial interface mode are determined by FMTC and FMTD pins.

•

Programmable mode: The device operation will be set by on chip control registers that can be

accessed through a two-wire command interface.

AUDIO DATA SAMPLE RATE AND MASTER CLOCK FREQUENCY

The AV2636 supports various audio data sample rate (fs) from 8kHz to 192kHz. The typical audio sample

rates are 32kHz, 44.1kH, 48kHz, 96kHz and 192kHz. The master clock (MCK) can be of 64fs to 384fs

depending on the operation mode. MCK is an input clock that operates the internal digital filters. Other on

chip clocks are also derived from MCK.

The on-chip master clock detection circuit automatically determines the relationship of master clock

frequency and audio sample rate. The counting error is set to be ±8 master clock cycles. If the error is

larger than the threshold, the DAC output will be shut down and auto muted.

The master clock has to be synchronized with the serial audio data frame signal ‘SF’. SF is also called left

and right data frame signal. The phase difference and clock jitters can be tolerated.

Master Clock Frequency MCK (MHz)

Sample

Rate (fs)

64fs

96fs

128fs

192fs

256fs

384fs

32 kHz

N/A

N/A

N/A

N/A

8.192

12.288

44.1 kHz

N/A

N/A

N/A

N/A

11.2896

16.9344

48 kHz

N/A

N/A

N/A

N/A

12.288

18.432

88.2 kHz

N/A

N/A

11.1896

16.9344

22.5792

33.8688

96 kHz

N/A

N/A

12.288

18.432

24.576

36.864

192 kHz

12.288

18.432

24.576

36.864

49.152*

73.728*

Note:

* Only available at programmable mode.

AVS Technology, Inc.

5-16

August 18, 2004

www.avstech.com