SNAA361A
april 2022 – may 2023
LMX2820
1
Abstract
Trademarks
1
Introduction
2
Reference Frequency
3
Standard LMX2820 Phase Noise Performance
4
Pre-multiplier Stage Performance
4.1
External VCO Loop Filter Design
4.2
Active Loop Filter Implementation
4.3
External VCO Performance Results
5
External PFD Topology
5.1
External PFD Loop Filter Modification
5.2
External PFD Measurement Results
6
Putting it Together in the Real World
6.1
Real-World Performance Results
6.2
Why use the Dual Approach?
7
Conclusion
8
Revision History
Application Note
LMX2820 RF Synthesizer Phase Noise Improvement With Alternative Topologies