Numerically controlled oscillator: Difference between revisions

Revision as of 01:45, 7 August 2011

Revision as of 04:55, 17 September 2011

Line 1:

A '''numerically- controlled oscillator''' ('''NCO''') is a digital [[signal generator]] which creates a [[Synchronous circuit|synchronous]] (i.e. clocked), discrete-time, discrete-valued representation of a [[waveform]], usually [[sinusoidal]].<ref name="IEEE">Jane Radatz, The IEEE Standard Dictionary of Electrical and Electronics Terms, IEEE Standards Office, New York, NY, 1997</ref> NCOs are often used in conjunction with a [[digital-to-analog converter]] (DAC) at the output to create a [[direct digital synthesizer]] (DDS).{{#tag:ref|While some authors use the terms DDS and NCO interchangeably,<ref name="latticeSC" /> by convention an NCO refers to the digital (i.e. the discrete-time, discrete amplitude) portion of a DDS<ref name="IEEE"/>}}

Numerically- controlled oscillators offer several advantages over other types of oscillators in terms of agility, accuracy, stability and reliability.<ref name="latticeSC">{{cite web|title=Numerically Controlled Oscillator

|url=http://www.latticesemi.com/products/intellectualproperty/ipcores/numericallycontrolledosci/index.cfm

|publisher=Lattice Semiconductor Corporation|year=2009}}</ref> NCOs are used in many communications systems including digital up/down converters used in 3G wireless and software radio systems, digital PLLs, radar systems, drivers for optical or acoustic transmissions, and multilevel [[Frequency-shift keying|FSK]]/[[Phase-shift keying|PSK]] modulators/demodulators.<ref name="latticeSC"/>

Line 90:

==See also==

*[[Direct digital synthesizer]]

*[[Digitally- controlled oscillator]]

*[[Digital-to-analog converter]]

Line 98:

{{good article}}

{{DEFAULTSORT:Numerically- Controlled Oscillator}}

[[Category:Digital signal processing]]

[[Category:Synthesizers]]