Project Overview | System Overview | Significant Milestones | Tools used During Design | Development and Testing | Problems and Tradeoffs
System Overview:
What exactly is a PLL?
The Phase Lock loop is a circuit that ensures that its output frequency is precisely related to its reference frequency.
This technology is found in many modern devices, including radio receivers, cell phones, walkie-talkies, CB radios, satellite receivers, GPS systems, etc.
TXCO/ Oscillator Driver
•Emits a reference voltage
Phase Frequency Detector (PFD)
•Compares the phase\frequency of the reference signal and the feedback signal.
Charge Pump
•Converts digital input to analog signal
Filter
•Integrates charge pump output signal
•Reduces spurious noise
Voltage Controlled Oscillator (VCO)
•Outputs a frequency that is roughly linearly related to input voltage.
Feedback Network
•Converts analog signal to digital signal
•Divides signal by an integer or rational number
