CDC421A100 Datasheet, PDF (1/15 Pages) Texas Instruments – Fully-Integrated, Fixed-Frequency, Low-Jitter Crystal Oscillator Clock Generator

CDC421AXXX
www.ti.com ....................................................................................................................................................................................................... SCAS875 – MAY 2009
Fully-Integrated, Fixed-Frequency, Low-Jitter
Crystal Oscillator Clock Generator
FEATURES
1
•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 (f_OUT) is
proportional to the frequency of the input crystal
(f_XTAL).
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.
External
Crystal
Crystal
Oscillator
Input
Feedback
Divider
Loop Filter
VCO
CLK
NCLK
CDC421Axxx
1
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.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009, Texas Instruments Incorporated