With the fundamentals of plls covered and a solid understanding of what problems they are able to address, the goals and. First time, every time practical tips for phase locked. The input signal vi with an input frequency fi is conceded by a phase detector. Phaselocked loop design fundamentals pages 1 12 text. Design of cmos phase locked loops by behzad razavi fills this void. A phaselocked loop pll is an electronic circuit with a voltage or voltagedriven oscillator that constantly adjusts to match the frequency of an input signal. A phaselocked loop pll is a device in which a periodic signal is generated and its phase is locked to the phase of an incoming signal. Design and simulations of a fastlocking digital phaselocked loop dpll based on 1, which covers a wide frequency range of 200mhz 2ghz and employs 0. Delaylocked loop delay line based phaselocked loop vcobased u d u d f ref f o f o f ref filter. Phaselocked loop design fundamentals introduction the purpose of this application note is to provide the electronic system designer with the necessary tools to design and evaluate phaselocked loops pll configured with integrated circuits. This is the frequency range around the free running frequency that the loop can track.
All digital phase locked loop design and implementation. Note that the duration of the start pulse jan 24, 2009ece department, winter school on nit durgapur vlsi systems design 2. The theory and mathematical models used to describe plls are of two types. It provides an extremely clear, intuitively appealing, onestop introduction to the subject that is both broad and deep. Lecture 080 all digital phase lock loops adpll reference 2 outline. This block is most appropriate when the input is a narrowband signal. Plls are used to generate, stabilize, modulate, demodulate, filter or recover a signal from a noisy communications channel where data has been interrupted. Design and implementation of an all digital phase locked.
The concept of phase locked loops pll first emerged in the early 1930s. Phase locked loop circuits university of california. But the technology was not developed as it now, the cost factor for developing this technology was very high. This application note discusses phase frequency detector characteristics that affect phaselocked loop pll dead band and jitter performance.
Design and implementation of an all digital phase locked loop using a pulse output direct digital frequency synthesizer akila gothandaraman university of tennessee knoxville this thesis is brought to you for free and open access by the graduate school at trace. Since the advancement in the field of integrated circuits, pll has become one of the main building blocks in the electronics technology. Cd74act297 digital phaselocked loop schs297d august 1998 revised june 2002 6 post office box 655303 dallas, texas 75265 detailed description continued thus, the simple firstorder phaselocked loop with an adjustable k counter is the equivalent of an analog. Once locked, pll tracks the frequency changes of the input signal. Applications of phaselocked loops play an increasingly important role in modern electronic systems, and the last 25 years have seen new developments in the underlying theories as well. Reference spurs in an integern university of adelaide. View notes minicircuits from ee 171 at university of california, santa cruz. Used with loop filters such as the k counter or n before m that output carry or borrow pulses. The root locus for a typical loop transfer function is found as follows.
Doesnt depend on the loop filter does depend on dc loop gain b. You specify the filters transfer function in the block mask using the lowpass filter numerator and lowpass filter denominator parameters. This phase locked loop keeps the generated signal and reference signal in a fixed relationship. Phaselocked loop design fundamentals application note, rev. The phaselocked loop pll block is a feedback control system that automatically adjusts the phase of a locally generated signal to match the phase of an input signal. Phase locked loop operating principle and applications. Digital phase locked loop devon fernandez and sanjeev manandhar december 8, 2003 1. Theory, design, and applicationsbook and disk best, roland e. Phaselocked loops are used for the demodulation of frequencymodulatedsignals, forfrequencysynthesis, andforotherapplications. Description download all digital phase locked loop design and implementation free in pdf format. In plls that employ charge pump loop filter designs. Fpgabased digital phaselocked loop analysis and implementation by dan hu thesis submitted in partial fulfillment of the requirements for the degree of master of science in electrical and computer engineering in the graduate college of the university of illinois at urbanachampaign, 2011 urbana, illinois advisers. Phase locked loop fundamentals the basic form of a phase locked loop pll consists of a voltage controlled oscillator.
Phase locked loop design fundamentals introduction the purpose of this application note is to provide the electronic system designer with the necessary tools to design and evaluate phase locked loops pll configured with integrated circuits. Implement phaselocked loop to recover phase of input. A phaselocked loop or phase lock loop pll is a control system that generates an output signal whose phase is related to the phase of an input signal. Phaselocked loops have many different applications and come to communications systems from the heritage of control and vibration theory where they are used to describe free. The lock range above and figure 3 the 565 integrated circuit pll contains almost all of the circuitry necessary to build a pll.
In its more general form figure 1, the pll may also contain a mixer and a digital divider. They have been widely used in communications, multimedia and many other applications. A phase locked loop is a feedback system combining a voltage controlled oscillator vco and a phase comparator so connected that the oscillator maintains a constant phase angle relative to a reference signal. Fr free running frequency 24 example vco ringoscillatorbased vco. Cmos phaselockedloop applications using the cd5474hchct4046a and cd5474hchct7046a w.
The phaselocked loop consists of a phase detector, a voltage controlled oscillator and, in between them, a low pass filter is fixed. Thus, a pll goes through three stages i free running, ii capture and iii locked or tracking. Fundamentals of phase locked loops plls fundamental phase locked loop architecture. Theprinciples of operation of phaselocked loops are discussed in the course notes. To understand the working of the phase locked loop system, let us consider the fm transmitter, which can be considered as one of the most frequently used pll applications pll circuit in fm transmitter is a closed loop feedback control system. In the steady state, the frequency of the vco is given by the expression. Minicircuits phase locked loop fundamentals the basic.
The fundamental design concepts for phase locked loops implemented with integrated circuits are outlined. A pll is a negative feedback system where an oscillatorgenerated signal is phase and frequency locked to a reference signal. The oscillator generates a periodic signal, and the phase detector compares the. Phaselocked loops presents the latest information on the basic theory and applications of plls. This project focuses on the design and simulation of a phase locked loop pll integrated circuit. A study of phaselocked loops and frequency synthesizers.
A delaylocked loop dll for the generation of multiple clock phasesdelays is proposed. Only a few discrete components are needed to set the vco free running frequency and loop filter. The zero in the numerator of the closedloop transfer function is the frequency in radianss where the gain of the integral and proportional paths are equal. Each of these parameters is a vector that lists the coefficients of the respective polynomial in order of descending exponents of the variable s. They can be configured as frequency multipliers, demodulators, tracking generators or clock recovery circuits. It is a musthave textbook for engineers interested in learning about the subject, and a useful reference for experts. What is phase locked loop pll pll is an electronic module circuit that locks the phase of the output to the input. Phase locked loop fundamentals the basic form of a phase locked loop pll consists of a voltage controlled oscillator vco, a phase detector pd, and a filter. Basic diagram of phase locked loop block diagram and working principle of pll. Loop comes from the feedback loop that controls the internal oscillators frequency to remain in sync with that of the input signal. Analysis, modelling and design by noorfazila kamal bachelor in computer engineering, universiti teknologi malaysia, 2000 thesis submitted for the degree of doctor of philosophy in. Enter your mobile number or email address below and well send you a link to download the free kindle app. Presentation outline what is phase locked loop pll. Phase locked loops, block diagram,working,operation,design.
Introduction to phaselock loop system modeling by wen li, senior system engineer, advanced analog product group and jason meiners, design manager, mixedsignal product group, texas instruments incorporated 1. Minicircuits phase locked loop fundamentals the basic form of a phase locked looppll consists of a. The majority of all pll design problems can be approached using the laplace transform technique. Lecture 430 phaselocked loops 42402 page 4309 ece 6412 analog integrated circuit design ii p. Introduction to phaselocked loop system modeling introduction phaselocked loops plls are one of the basic building blocks in modern electronic systems. Introduction phaselock loops plls have been one of the basic building blocks in modern electronic systems.
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