3rd Order PLL

The Third Order PLL clock recovery method models the response of an ideal Type III, third-order hardware 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 3rd Order PLL clock recovery mode is selected, the dialog box has these controls:

• Symbol Rate — Enter the signal's expected baud 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.

• Clock Skew — For PAM type signals, this can be used to center the eye opening at the clock locations by shifting the clocks relative to the data.

• Natural Frequency — ω_n in the previous equations.

• Pole Frequency — ω_p in the previous equations.

• Damping Factor — ζ in the previous equations.

Advanced Settings

• Deemphasis Removal
• Edge Direction
• Transition Density Dependent
• Settling Time
• Idle Clock Count
• Apply SSC Correction
• Use Advanced Clock Recovery for Closed Eyes