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FEATURES

APPLICATIONS

DESCRIPTION

Crystal

Oscillator

Input

Feedback

Divider

LoopFilter

VCO

External

Crystal

CLK

NCLK

CDC421AXXX

Fully-Integrated, Fixed-Frequency, Low-Jitter

Crystal Oscillator Clock Generator

• Low-Cost, Low-Jitter Frequency Multiplier

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• Single 3.3-V Supply

• High-Performance Clock Generator,

Incorporating Crystal Oscillator Circuitry with

Integrated Frequency Synthesizer

The

CDC421Axxx

is

a

high-performance,

low-phase-noise clock generator. It has an integrated

• Low Output Jitter: As low as 380 fs (RMS

low-noise,

LC-based

voltage-controlled

oscillator

integrated between 10 kHz to 20 MHz)

(VCO) that operates within the 1.75 GHz to 2.35 GHz

• Low Phase Noise at 312.5 MHz:

frequency range. It has an integrated crystal oscillator

–

Less than –120 dBc/Hz at 10 kHz and

that operates in conjunction with an external AT-cut

–147 dBc/Hz at 10-MHz offset from carrier

crystal to produce a stable frequency reference for a

phase-locked

loop

(PLL)-based

frequency

• Supports Crystal or LVCMOS Input

synthesizer.

The

output

frequency

is

Frequencies at 31.25 MHz, 33.33 MHz, and

proportional to the frequency of the input crystal

35.42 MHz

• Output Frequencies: 100 MHz, 106.25 MHz,

The device operates in 3.3-V supply environment and

125 MHz, 156.25 MHz, 212.5 MHz, 250 MHz, and

is characterized for operation from –40°C to +85°C.

312.5 MHz

The CDC421Axxx is available in a QFN-24 4-mm ×

• Differential Low-Voltage Positive Emitter

4-mm package.

Coupled Logic (LVPECL) Outputs

The CDC421Axxx differs from the CDC421xxx in

• Fully-Integrated Voltage-Controlled Oscillator

the following ways:

(VCO): Runs from 1.75 GHz to 2.35 GHz

• Device Startup

• Typical Power Consumption: 300 mW

The CDC421Axxx has an improved startup circuit

• Chip Enable Control Pin

to enable correct operation for all power-supply

ramp times.

• Available in 4-mm × 4-mm QFN-24 Package

• ESD Protection Exceeds 2 kV (HBM)

• Industrial Temperature Range: –40°C to +85°C

CDC421Axxx

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2009, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.