pll & dll design in simulink matlab
TRANSCRIPT
DESIGN AND SIMULATION OF PLL & DLL USING MATLAB SIMULINK
MADE BY :- KARTIK PAL
(131029)
PHASE LOCKED LOOP (PLL)
INTRODUCTION
What is a PLL? Block Diagram of PLL Parts of a PLL PLL Design in Simulink
• PLL Without divider design• Waveform• PLL With divider design• Waveform
What is a PLL? A phase lock loop (PLL) is a control
system that generates an output signal whose phase is related to the phase of an input signal
Block Diagram
Parts of a PLL Phase Detector Filter Voltage Controlled Oscillator Programmable Counter/Divider
Parts of a PLL Phase Detector
Acts as comparator Produces a voltage proportional to the phase
difference between input and output signal Voltage becomes a control signal
Parts of a PLL Filter
Determines dynamic characteristics of PLL Specify Capture Range (bandwidth) Specify Tracking Range
Receives signal from Phase Detector and filters accordingly
Parts of a PLL Voltage Controlled Oscillator
Set tuning range Set noise margin Creates low noise clock oscillation
Divider Divides the VCO output by the degree of the open
loop gain Feedback loop allows phase comparison
Parts of a PLL
PLL Design in SimulinkPLL Without Divider design
WaveformInput signal
Phase Detector
Control signal
Synthesized Signal
Spectrum Analyser
PLL With Divider Design
WaveformInput signal
Phase Detector
Control signal
Synthesized Signal
Spectrum Analyser 1
DELAY LOCKED LOOP (DLL)
INTRODUCTION What is a DLL? Block Diagram of DLL Parts of a DLL DLL Design in Simulink
• DLL design• Waveform
What is DLL?
A delay-locked loop (DLL) is a digital circuit similar to a Phase-Locked Loop (PLL), with the main difference being the absence of an internal voltage-controlled oscillator(VCO), replaced by a voltage-controlled delay line (VCDL).
Block Diagram
Parts of a PLL Phase Detector(PD) Charge pump(CP) Loop Filter(LF) Voltage Controlled Delay Line(VCDL)
Parts of a DLL Phase Detector(PD)
Acts as comparator Produces a voltage proportional to the phase
difference between input and output signal Voltage becomes a control signal
Parts of a DLL Charge Pump(CP)
• The outputs of the PD are directly connected to the inputs of CP, and CP prepares the input of LF which is proportional to the width of the PD output signals (inputs of CP).
• In Matlab Simulink, a simple adder can be used to model CP
Parts of a DLL Loop Filter(LF)
• Loop filter is a simple integrator that performs integral of the output signals from CP.
• In the other word the loop filter’s capacitor gets charged or discharged if there is a time lead or time lag between the reference signal and the output of the delay line.
Parts of a DLLVoltage Controlled Delay Line(VCDL)
• Voltage controlled delay line (VCDL) includes a chain of delay cells.
• Usually all of the delay cells have the same structure.
• In locked condition, the output of the last delay stage is exactly one cycle lagged from the reference clock (Vin).
DLL Design in Simulink
WaveformInput signal & Output signal