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27 MHz

Crystal

CDCE906

16.9344 MHz (384fs)

33.8688 MHz (768fs)

11.2896 MHz (256fs)

27 MHz

DVD−DSP

MPEG/AC−3

Audio Dec

Karaoke

DSP

PCM1716

Front

Surround

Center

Subwoofer

CPU Clock

64 MHz

i.e. audio rate: 44.1 kHz

Clock Inputs (CLK_IN0 and CLK_IN1)

XO

or

2LVCMOS

or

Differential

Input

CLK_IN0

CLK_IN1

Input source select

(from EEPROM)

C

X0

C

X1

crystal

unit

C

ICB

C

ICB

CDCE906

SCAS814H – NOVEMBER 2005 – REVISED DECEMBER 2007

Typical applications for the CDCE906 are digital HDTV systems, gaming consoles, DVD players, DVD add-on

cards for multimedia PCs, and step-top boxes.

Figure 14. CDCE906 System Application Block Diagram

The CDCE906 features two clock inputs which can be used as:

• Crystal oscillator input (default setting)

• Two independent single-ended LVCMOS inputs

• Differential signal input

The dedicated clock input can be selected by the input signal source Bit [7:6] of Byte 11.

Crystal Oscillator Inputs

The input frequency range in crystal mode is 8 MHz to 54 MHz. The CDCE906 uses a Pierce-type oscillator

circuitry with included feedback resistance for the inverting amplifier. The user, however, has to add external

be calculated:

device including the board capacitance (stray capacitance of PCB).

It is important to use a short PCB trace from the device to the crystal unit to keep the stray capacitance of the

oscillator loop to a minimum.

Figure 15. Crystal Input Circuitry

22

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