5th Order PLL

The Fifth Order PLL clock recovery method is the same as the PCIe 5/6 CXL Behavioral SRIS CC clock recovery methods except that it gives you control over the CDR (clock and data recovery) filter angular frequency parameters ω₀, ω₁, and ω_LF instead of using the values in the PCIe specification.

When the 5th 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.
ω₀, ω₁, and ω_LF:

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 Fifth Order PLL's Jitter Transfer Function looks like this:

The damping factor parameters are (as with the PCIe Gen 5/6 SRIS and CC Behavioral CDR at 32.0 and 64.0 GT/s):
- ζ₁ = 1∕√2
- ζ₂ = 1
As an example, the angular frequency parameters for PCIe Gen 5/6 SRIS and CC Behavioral CDR at 64.0 GT/s are:
- ω₀ = 10 × 10⁶ × 2π
- ω₁ = 3.88 × 10⁶ × 2π
- ω_LF = 87 × 10³ × 2π

5th Order PLL

Advanced Settings