Characterize Phase-Locked Loop Systems Using Real Time Oscilloscopes

Phase-locked loops (PLL) are frequently used in communication applications. For example, they recover the clock from digital data signals (CDR), recover the carrier from satellite transmission signals, perform frequency and phase modulation and demodulation, and synthesize exact frequencies for receiver tuning. The PLL characteristics include bandwidth, noise, acquisition range and speed, dynamic range, stability and accuracy. After introducing the operating principles of the PLL, this note describes how to accomplish typical PLL characterization tests using the TDSJIT3 Jitter and Timing Analysis Application running on real-time oscilloscopes.