The AD9850 complete direct digital synthesizer (DDS) is a popular device used to implement a low cost, high speed, digital synthesis system. Clocking the AD9850 at its maximum rate of 125 MHz may present some technical challenges especially in applications where the phase noise of the sine output is a major concern. Numerous requests for recommended high speed clocking solutions to drive the AD9850 have prompted this application note.

DescriptionVL-821 Ethernet, GE, SynchE Storage Area Networking Digital Video Broadband Access Microprocessors/DSP/FPGA Page1 VDD Output GndCrystal E/D PLLVectron International 267 Lowell Road, Hudson, NH 03051 Tel: 1-88-VECTRON-1 http://www.vectron.comPage2Performance Speci cationsTable 1. Electrical Performance, 3.3V OptionParameterSymbolMinTypicalMaximumUnits SupplyOperating Supply Voltage1VDD2.973.33.63VAbsolute Maximum Operating Voltage-0.055.0VSupply Current, Output Enabled<30 MHz30.01 t

The CY2037 is an EPROM programmable, high accuracy, PLL-based die designed for the crystal oscillator market. The die attaches directly to a low-cost 10-30 MHz crystal and can be packaged into 4-pin through-hole or surface mount packages. The oscillator devices can be stocked as blank parts and custom frequencies programmed in-package at the last stage before shipping. This enables fast-turn manufacture of custom and standard crystal oscillators without the need for dedicated, expensive crystals

FeaturesApplicationsPerformance Speci cationsFrequency Stabilities1ParameterMinTypicalMaxUnitsConditionvs. operating temperature range (referenced to +25C)-1.5-1.0-2.5-1.0-1.0-0.5+1.5+1.0+2.5+1.0+1.0+0.5ppmppmppmppmppmppm-40 to +85C-40 to +85C-20 to +70C-20 to +70C0 to +50C0 to +50COptions5Initial tolerancevs. supply voltage changevs. load changevs. aging / 1 Year-2.5-0.5-0.2-1.0+2.5+0.5+0.2+1.0ppmppmppmppmat time of shipment, nominal EFCVS 5% Load 10%after 30 days of operation1 (Stratum 3 TCXO)

Features: Frequency range 559-561 MHz, tuning voltage .5-3.5 Vdc, and SUB-L style package. Applications: satellite communications, portable radios, and RF modems.

Miniature ceramic package, Highly reliable with seam welding, CMOS output, Supply voltage VCC =3.3V

Compact OCVCXO(36.1x27.2x20.2mm), High stability, Solder sealing type.

The Intersil HSP45106/883 is a high performance 16-bitquadrature Numerically Controlled Oscillator (NCO16). TheNCO16 simplifies applications requiring frequency andphase agility such as frequency-hopped modems, PSKmodems, spread spectrum communications, and precisionsignal generators.

Features: Frequency range 310-366 MHz, tuning voltage .5-4.5 Vdc, and MINI-16 style package. Applications: satellite modems and mobile radios.

A 1.8V LVDS, crystal controlled, low current, low jitter oscillator with precise rise and fall times demanded in networking applications, such as Gigabit Ethernet and Fibre Channel.