JTOL Application Notes
- Microchip
- https://ww1.microchip.com/downloads/en/Appnotes/en567015.pdf
- USB3
- Calibration of jitter sources is critical
- Anritsu
- MP1900A
- https://dl.cdn-anritsu.com/en-en/test-measurement/files/Application-Notes/Application-Note/mp1900a-jitter-tolerance-ef1100.pdf
- (1) jitter tolerance testing isn't just SJ
- (2.1) Sinusoidal Jitter
- "When the input Data signal jitter frequency and amount are within the Loop Bandwidth, an error does not occur due to a phase mismatch because recovered clock tracks input Data signal in terms of jitter"
- "jitter tolerance test for PCI Express, specifies applying two SJs"
- More than one sj's at a time!
- (2.2) Random Jitter
- "For RJ, the CEI 3.0 jitter tolerance test standardizes use of a High Pass Filter (HPF) to remove RJ components within the PLL band as shown below and applies only PLL out-of-band components as the load"
- The MP1900A scope can apply different amounts of RJ in different frequency bands!
- (2.3) BUJ - Bounded Uncorrelated Jitter
- crosstalk!
- (2.4) Half Period Jitter (F/2 Jitter) or HPJ
- due to half rate clock
- (3) Tips for Jitter Tolerance Measurement
- (3.2) "At jitter tolerance measurement, the amount of jitter is changed until the designated error condition is detected by searching. There are two search methods: Downwards from large to small values, and Upwards from small to large values. The search steps for both the Downwards and Upwards searches can be specified as either Linear using a fixed value, or as Logarithmic using a value changing at a fixed ratio."
- Interesting that both up and down searches are available
- Interesting that both linear and Logarithmic steps are also available.
- Tek
- https://download.tek.com/manual/PCIe_Gen4_Base_Rx_Help_EN-US_077-1773-02_077177302.pdf
- Interesting how different frequency ranges uses a different step size.
- Search Algorithms options, {Binary, Downwards Linear, Downwards Log, Upwards Log, Upwards Linear, Binary + Linear}
- It would be helpful to plot the JTOL performance as the data comes in.
