Scicos Diagram
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Discrete Voltage Controlled Oscillator

Module

• Modnum

Contents

• Discrete Voltage Controlled Oscillator
  • Module
  • Description
  • Context
  • Scope Results
  • Used blocks
  • See Also
  • Authors

Description

This diagram is an open loop model of a discrete Voltage Controlled Oscillator.
The regular output voltage can be described with this continuous equation :

$$\begin{eqnarray} y_{s}\left(t\right)=\cos \left[\left(\omega_{0}t\right)+\int^{t}_{0} k_{v} u_{3}\left(\tau\right)+n(\tau)d\tau\right] \end{eqnarray}$$

The noise added in the the tunning voltage is a White Gaussian Noise.
The time domain integration of the input voltage is realized with the "EULERINTEGRAL" block that uses a discrete backward-Euler rule and the "VCOEVT" block produces events corresponding to zero crossings of the output waveform with a discrete method of detection.

Context

Fo = 10e6;
To = 1 / Fo;
wo=2*%pi * Fo;
alpha=60e6;
kv=60e6
j_vco=100e6;
N=3;
Nsampl = 80;
Tsampl = To/(Nsampl);
Fsampl = 1 / Tsampl;
Tfin=15*To

Scope Results

Figure : Input and output voltage of VCO

Figure : Events generated by the VCOEVT block

Figure : Events generated by the frequency divider block

Used blocks

• EULERINTEGRAL_f - Single step integrator block by Euler method
• NOISEBLK_f - Gaussian White Noise Generator block
• Time_f - Discrete time estimator bloc
• VCOEVT_f - Discrete zero crossing block

See Also

• scicos_vco - Continuous Voltage Controlled Oscillator (Scicos Diagram)
• VCO_c - Discrete Voltage Controlled Oscillator block (Scicos Block)

Authors

IRCOM Group Alan Layec