Content deleted Content added
Kryptonsa36 (talk | contribs) m Kryptonsa36 moved page Numerically-controlled oscillator to Numerically controlled oscillator over redirect |
m compound modifier |
||
| (2 intermediate revisions by 2 users not shown) | |||
Line 22:
[[Image:Phase Accum Graph.png|frame|Figure 2: Normalized phase accumulator output]]
The adder is designed to overflow when the sum of the [[absolute value]] of its operands exceeds its capacity (2<sup>N</sup>−1). The overflow bit is discarded so the output word width is always equal to its input word width. The remainder <math>\phi _n</math>, called the residual, is stored in the register and the cycle repeats, starting this time from <math>\phi _n</math> (see figure 2).<ref name="Grzeg"/> Since a phase accumulator is a [[finite
:<math>\mbox{GRR}=\frac{2^N}{\mbox{GCD}(\Delta F,2^N)}</math>
Line 35:
==Phase-to-amplitude converter==
The phase-amplitude converter creates the sample-___domain waveform from the truncated phase output word received from the PA. The PAC can be a simple [[read only memory]] containing 2<sup>M</sup> contiguous samples of the desired output waveform which typically is a sinusoid. Often though, various tricks are employed to reduce the amount of memory required. This include various trigonometric expansions,<ref>{{ cite patent | inventor-last = Miller | inventor-first = B. M. | issue-date = October 14, 2008 | title = Numerically controlled oscillator and method of operation | country-code = US | patent-number = 7437391 }}</ref> trigonometric approximations<ref name="Grzeg">{{
==Spurious products==
Line 66:
==See also==
* [[Direct digital synthesis]] (DDS)▼
* [[Digital-to-analog converter]] (DAC)
* [[Digitally controlled oscillator]] (DCO)
▲* [[Direct digital synthesis]] (DDS)
==References==
| |||