A numerically controlled oscillator is a digital circuit that generates a precise, variable-frequency waveform, usually a sine wave, from a fixed clock reference. It typically consists of a phase accumulator that steps through values based on a tuning word, followed by a phase-to-amplitude converter like a lookup table. NCOs are prized in software-defined radios and digital synthesizers for their extreme frequency agility and phase continuity.
By changing the tuning word on the NCO, we can frequency-hop the transmitter without any settling time delay.
Also heard as
- numerically controlled oscillator
Related terms
VCO
A voltage-controlled oscillator is a circuit that changes its output frequency based on a DC input voltage.
DDS
A technique for generating arbitrary periodic waveforms from a single, fixed-frequency reference clock.
Clock generator
A circuit or chip that produces the primary timing signals for a digital system.