All About Circuits

Latest Telecom Technical Articles

Categories

Operation of a Linear Phase Detector for Clock and Data Recovery

Operation of a Linear Phase Detector for Clock and Data Recovery

Learn how the Hogge detector addresses the challenges of clock and data recovery (CDR) for data signals with limited clock information.


Using the Arduino Uno Q to Build a DDS Sine Wave Generator

Using the Arduino Uno Q to Build a DDS Sine Wave Generator

In this project, we'll construct and test a microcontroller-based system that digitally generates analog signals.


Projects Apr 19, 2026 by Don Wilcher
Introduction to Clock and Data Recovery

Introduction to Clock and Data Recovery

Learn how PLLs enable communication in which a clock signal is not transmitted with the data. We’ll look specifically at return-to-zero (RZ) and non-return-to-zero (NRZ) data formats.


Preventing Runt Pulses in Phase/Frequency Detectors

Preventing Runt Pulses in Phase/Frequency Detectors

This article explains the importance of incorporating delay into the feedback path of a phase/frequency detector (PFD) and examines its effect on performance.


Introduction to Phase/Frequency Detectors

Introduction to Phase/Frequency Detectors

Learn how using a phase/frequency detector (PFD) in place of a phase detector improves the acquisition range of a PLL.


Introduction to the RS Flip-Flop Phase Detector

Introduction to the RS Flip-Flop Phase Detector

Learn about this simple sequential phase detector and how it compares to the XOR gate. We'll also examine some key limitations and circuit implementations.


Understanding the Exclusive-OR Phase Detector

Understanding the Exclusive-OR Phase Detector

This article explores the operation of the simplest digital phase detector: the exclusive-OR (XOR) gate.


Diode-Based Phase Detectors: Key Principles and Example Circuits

Diode-Based Phase Detectors: Key Principles and Example Circuits

We examine phase detectors that leverage either the nonlinear characteristics or switching capabilities of diodes to perform multiplication.


Using Gilbert Multipliers as Phase Detectors in PLLs

Using Gilbert Multipliers as Phase Detectors in PLLs

This article explores the operation of the Gilbert-cell phase detector for both small and large signals.


Introduction to the Gilbert Multiplier

Introduction to the Gilbert Multiplier

This article explores the Gilbert cell, a widely used analog multiplier circuit.


Second-Order Type-2 PLLs: Bode Diagrams, Bandwidth, and Overshoot

Second-Order Type-2 PLLs: Bode Diagrams, Bandwidth, and Overshoot

Learn how to select the zero frequency, damping factor, and loop bandwidth for one of the most popular PLL configurations.


Introduction to Second-Order Type-2 PLLs

Introduction to Second-Order Type-2 PLLs

This article explains how Type-2 PLLs with an integrator loop filter outperform Type-1 systems. To do so, we'll examine the PLL behavior for frequency step and frequency ramp inputs.


Understanding the Time-Domain Response of PLLs With Lag-Lead Filters

Understanding the Time-Domain Response of PLLs With Lag-Lead Filters

In this article, we examine how adding a zero to the PLL loop filter affects the transient behavior and steady-state errors.


Exploring the Bode Plots of PLLs With a Lag-Lead Loop Filter

Exploring the Bode Plots of PLLs With a Lag-Lead Loop Filter

In this article, we derive design equations for a second-order PLL with a lag-lead filter by examining its Bode plots.


Introducing the Lag-Lead Filter

Introducing the Lag-Lead Filter

Learn how using a pole-zero loop filter improves PLL performance and design flexibility over the simpler lag filter.


Analyzing the Lag Filter’s Effect on PLL Performance

Analyzing the Lag Filter’s Effect on PLL Performance

In this article, we evaluate the designs of two simple frequency synthesizers to learn how a second-order PLL with a lag filter can provide a faster rise time than a first-order PLL.


Understanding the Limitations of the Second-Order Type-1 PLL With a Lag Filter

Understanding the Limitations of the Second-Order Type-1 PLL With a Lag Filter

In this article, we analyze the steady-state errors and Bode plots for a second-order PLL with a simple, first-order loop filter.


Introduction to Second-Order Type-1 PLLs

Introduction to Second-Order Type-1 PLLs

Learn how adding a lowpass loop filter to a PLL with a single integrator impacts both the frequency-domain and time-domain response.


Understanding the Limitations of the First-Order PLL

Understanding the Limitations of the First-Order PLL

Higher-order PLLs are more commonly used than first-order PLLs. To explain why, we explore the first-order PLL's behavior in response to two inputs: a frequency step and frequency ramp.


Analyzing First-Order PLLs Using Linear Models

Analyzing First-Order PLLs Using Linear Models

In this article, we'll use the linearized model of a first-order PLL to understand its response to a simple input change. We'll then use Matlab simulations to visualize the signals.