:CMODe:CRECovery:PLL:MODE

:CMODe CRECovery Commands

Command Syntax

:CMODeN:CRECovery:PLL:MODE {JTF | OJTF}

Where N identifies a specific common-mode waveform in the form "<connection1-8>_<ch1|ch3|ch5|ch7>". With connection 1, the connection number part (that is, "1_") is optional, and you can simply use the channel number "<ch1|ch3|ch5|ch7>". When two channels are paired to create a differential waveform and a common-mode waveform, the odd-numbered channel is used when specifying the waveform. For example, connection 5 common-mode waveform 3 (from the pairing of channels 3 and 4) is CMODe5_3.

Query Syntax

:CMODeN:CRECovery:PLL:MODE?

Description

Chooses whether whether to specify the PLL's response in terms of either the JTF's 3 dB bandwidth and its peaking or the OJTF's 3 dB bandwidth and its damping factor.

  • JTF (Jitter Transfer Function) — This is the closed-loop transfer function of the PLL. It is the ratio of the jitter on the PLL's output clock to the jitter on the input signal.

    This function generally has a low-pass effect. That is, JTF is at unity over low frequencies, but as the jitter increases to higher frequencies, the jitter on the recovered clock will decrease in magnitude.

    Use the :CMODe:CRECovery:SOPLl:JTF:PEAKing command to specify the peaking of the JTF.

  • OJTF (Observed Jitter Transfer Function, sometimes referred to as the Error Function) — This is the jitter between the PLL's input signal and PLL's output clock. It is equivalent to the PLL's Error Function (OJTF = EF = 1 – JTF).

    This function generally has a high-pass effect. That is, OJTF is at unity over high frequencies, but as the jitter decreases to lower frequencies, the jitter on the displayed waveform will decrease in magnitude.

    Use the :CMODe:CRECovery:SOPLl:OJTF:DFACtor command to specify the damping factor of the JTF.

Example Command Sequence

:CMODe1:CRECovery:MODE SOPLl
:CMODe1:CRECovery:PLL:MODE JTF
:CMODe1:CRECovery:SOPLl:JTF:LBANdwidth 2.837E+6
:CMODe1:CRECovery:SOPLl:JTF:PEAKing 1.25