Numerically controlled oscillator

A numerically controlled oscillator (NCO) is a digital signal generator which creates a synchronous (i.e., clocked), discrete-time, discrete-valued representation of a waveform, usually sinusoidal.[1] NCOs are often used in conjunction with a digital-to-analog converter (DAC) at the output to create a direct digital synthesizer (DDS).[3]

Numerically controlled oscillators offer several advantages over other types of oscillators in terms of agility, accuracy, stability and reliability.[2] NCOs are used in many communications systems including digital up/down converters used in 3G wireless and software radio systems, digital phase-locked loops, radar systems, drivers for optical or acoustic transmissions, and multilevel FSK/PSK modulators/demodulators.[2]

  1. ^ a b Radatz, J. (1997). The IEEE Standard Dictionary of Electrical and Electronics Terms. New York, NY: IEEE Standards Office.
  2. ^ a b c "Numerically Controlled Oscillator". Lattice Semiconductor Corporation. 2009.
  3. ^ While some authors use the terms DDS and NCO interchangeably,[2] by convention an NCO refers to the digital (i.e. the discrete-time, discrete amplitude) portion of a DDS[1]