Abstract
The sampling nature of the phase-frequency detector (PFD) degrades the stability of the charge-pump phase-locked loop (CPPLL). This paper analyzes the effect of the PFD sampling on the CPPLL stability by using z-transform. The PFD is modeled as a zero-order hold to perform the z-domain analysis. The stability boundary predicted by the analysis is accurate and verified by simulations using Cadence Spectre. In addition, a physical interpretation of how sampling destabilizes an otherwise stable continuous feedback system is provided in time domain, which brings valuable insight into the operation of sampled feedback systems like CPPLL.
| Original language | English |
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| Title of host publication | 2018 IEEE International Symposium on Circuits and Systems, ISCAS 2018 - Proceedings |
| Place of Publication | Piscataway |
| Publisher | Institute of Electrical and Electronics Engineers |
| Pages | 1-5 |
| Number of pages | 5 |
| ISBN (Electronic) | 978-1-5386-4881-0 |
| ISBN (Print) | 978-1-5386-4882-7 |
| DOIs | |
| Publication status | Published - 26 Apr 2018 |
| Event | 2018 IEEE International Symposium on Circuits and Systems (ISCAS 2018) - Florence Conference Center, Florence, Italy Duration: 27 May 2018 → 30 May 2018 https://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=8334884 |
Conference
| Conference | 2018 IEEE International Symposium on Circuits and Systems (ISCAS 2018) |
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| Abbreviated title | ISCAS 2018 |
| Country/Territory | Italy |
| City | Florence |
| Period | 27/05/18 → 30/05/18 |
| Internet address |
Funding
ACKNOWLEDGMENT We would like to sincerely thank STW financial assistance to our project.
Keywords
- Phase-frequency detector
- phase-locked loop
- sampling
- zero-order hold