Relation To Earlier VCO Designs
Many voltage-controlled oscillators for electronic music are based on a capacitor charging linearly in an op-amp integrator configuration. When the capacitor charge reaches a certain level, a comparator generates a reset pulse, which discharges the capacitor and the cycle begins again. This produces a rising ramp (or sawtooth) waveform, and this type of oscillator core is known as a ramp core.
A common DCO design uses a programmable counter IC such as the 8253.
This provides stable digital pitch generation but square waves only. Further analog waveshaping is provided afterward. Sawtooth generation is formed by amplifying the integration of the original signal. A control voltage is used to control the sawtooth amplitude since no reset comparator and feedback loop are provided as with an actual analog oscillator core.
This method differs from an analog core (which dictates pitch through oscillatory feedback) to a pitch directly produced by a counter and controlling CPU.
Read more about this topic: Digitally Controlled Oscillator
Famous quotes containing the words relation to, relation, earlier and/or designs:
“Among the most valuable but least appreciated experiences parenthood can provide are the opportunities it offers for exploring, reliving, and resolving one’s own childhood problems in the context of one’s relation to one’s child.”
—Bruno Bettelheim (20th century)
“Any relation to the land, the habit of tilling it, or mining it, or even hunting on it, generates the feeling of patriotism. He who keeps shop on it, or he who merely uses it as a support to his desk and ledger, or to his manufactory, values it less.”
—Ralph Waldo Emerson (1803–1882)
“If in the earlier part of the century, middle-class children suffered from overattentive mothers, from being “mother’s only accomplishment,” today’s children may suffer from an underestimation of their needs. Our idea of what a child needs in each case reflects what parents need. The child’s needs are thus a cultural football in an economic and marital game.”
—Arlie Hochschild (20th century)
“His designs were strictly honourable, as the phrase is; that is, to rob a lady of her fortune by way of marriage.”
—Henry Fielding (1707–1754)