TSMC GF Intel Samsung Fractional-N Frequency Synthesizer PLL
Predicting PLL reference spur levels due to leakage current
Michel Azarian, Sr. Applications Engineer, and Will Ezell, Mixed Signal Products, Linear Technology
EETimes (11/9/2012 12:22 PM EST)
A simple model can be used to accurately predict the level of reference spurs due to charge pump and/or op-amp leakage current in a phased-locked loop system. Knowing how to predict these levels helps pick loop parameters wisely during the early stages of a PLL system design.
Quick review of PLLs
The phase-locked loop (PLL) is a negative feedback system that locks the phase and frequency of a higher frequency device (usually a voltage controlled oscillator (VCO) whose phase and frequency are not very stable over temperature and time to a more stable and lower frequency device (usually a temperature compensated or oven-controlled crystal oscillator, (TCXO or OCXO). As a black box, the PLL can be viewed as a frequency multiplier.
![]() |
E-mail This Article | ![]() |
![]() |
Printer-Friendly Page |
Related Articles
- Specifying a PLL Part 1: Calculating PLL Clock Spur Requirements from ADC or DAC SFDR
- Keeping leakage current under control
- Analysis and Summary on Clock Generator Circuits and PLL Design
- Bandgap Reference (BGR) Circuit Design and Transient Analysis in 90nm VLSI Technology
- Achieving Your Low Power Goals with Synopsys Ultra Low Leakage IO
New Articles
- Nexus: A Lightweight and Scalable Multi-Agent Framework for Complex Tasks Automation
- How the Ability to Manage Register Specifications Helps You Create More Competitive Products
- EAVS - Electra IC Advanced Verification Suite for RISC-V Cores
- Why RISC-V is a viable option for safety-critical applications
- Dimensioning in 3D space: Object Volumetric Measurement by Leveraging Depth Camera-based Reconstruction on NVIDIA Edge devices