Explicit 3rd Order PLL

The Explicit 3rd Order PLL recovery method lets you provide a clock from the circuit that you are measuring and apply a third-order PLL.

You can specify the PLL's response in terms of its Natural Frequency (ω_n), Pole Frequency (ω_p), and Damping Factor (ζ).

Note that the following equations use the angular frequency, ω (in radians/sec) which is equivalent to 2πf, where f is frequency (in Hertz).

The Third Order PLL's Jitter Transfer Function looks like this:

The Third Order PLL's Observed Jitter Transfer Function (or Error Function, hence, E(s)) looks like this:

When the Explicit 3rd Order PLL clock recovery mode is selected, the dialog box has these controls:

Symbol Rate — Displays the signal's measured symbol rate.

For explicit clock recovery methods, Clock Frequency is used in place of Symbol Rate.

The Select From List drop-down menu lets you select typical rates for standard communication interface technologies. The Auto Set Symbol Rate button runs a data rate measurement and populates the Symbol Rate field with the data rate measured on the input signal.
Natural Frequency — ω_n in the previous equations.
Pole Frequency — ω_p in the previous equations.
Damping Factor — ζ in the previous equations.

Explicit Clock Settings

Explicit Clock Source — This specifies the input source of the provided clock to be used for clock recovery.
Edge Direction — Lets you specify the edges used in the explicit clock: Rising edges, Falling edges, or Both rising and falling edges.
Clock Multiplier — This specifies the multiplier of the provided clock to be used.
Clock Frequency — The clock frequency of the PLL.