Scicos Block
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Second order Loop Filter for PLL type 2 block





This block realizes a continuous second order loop filter defined by the following electrical circuit :

Figure 1: Passive second order loop filter

Because this circuit can be explicitly expressed with linear ordinary differential equations, it is able to be described by a tranfert function.
The transfer function of this filter is :

F(s)=\dfrac{1+\tau_{1}s}{\tau s\left(1+\tau_{2}s\right)},

where the zero $ \tau_{1}$ and the poles $ \tau\,\tau_{2}$ are computed according to the dialogue parameters and with the hep of the Scilab macro calcul_3eme_ordre.

The interfacing function of this block also allows to plot the different Bode diagrams of the linear model of a third order type 2 PLL.
This can be useful for the calibration of the the attenuation at cut-off frequency of the closed-loop transfert function.

Dialog box


Default properties

Interfacing function

See also


A. Layec