1FEATURES

2· Single 3.3-V Supply

· High-Performance Clock Generator,

Incorporating Crystal Oscillator Circuitry with

Integrated Frequency Synthesizer

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

integrated between 10 kHz to 20 MHz)

· Low Phase Noise at 312.5 MHz:

– Less than –120 dBc/Hz at 10 kHz and

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

· Supports Crystal or LVCMOS Input

Frequencies at 31.25 MHz, 33.33 MHz, and

35.42 MHz

· Output Frequencies: 100 MHz, 106.25 MHz,

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

312.5 MHz

· Differential Low-Voltage Positive Emitter

Coupled Logic (LVPECL) Outputs

· Fully-Integrated Voltage-Controlled Oscillator

(VCO): Runs from 1.75 GHz to 2.35 GHz

· Typical Power Consumption: 300 mW

· Chip Enable Control Pin

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

· ESD Protection Exceeds 2 kV (HBM)

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

APPLICATIONS

· Low-Cost, Low-Jitter Frequency Multiplier

DESCRIPTION

The CDC421Axxx is a high-performance,

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

low-noise, LC-based voltage-controlled oscillator

(VCO) that operates within the 1.75 GHz to 2.35 GHz frequency range. It has an integrated crystal oscillator

that operates in conjunction with an external AT-cut

crystal to produce a stable frequency reference for a

phase-locked loop (PLL)-based frequency

synthesizer. The output frequency (fOUT) is

proportional to the frequency of the input crystal (fXTAL).

The device operates in 3.3-V supply environment and

is characterized for operation from –40°C to +85°C. The CDC421Axxx is available in a QFN-24 4-mm ×

4-mm package.

The CDC421Axxx differs from the CDC421xxx in the following ways:

· Device Startup

The CDC421Axxx has an improved startup circuit

to enable correct operation for all power-supply

ramp times.