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The Holiday Season Analog Alarm! A Gift-Defending System

The Holiday Season Analog Alarm! A Gift-Defending System

Nowhere to hide presents this holiday season? No problem! This alarm will sound anytime a loved one tries to get a sneak peek at his or her surprise.


Projects Dec 05, 2016 by Ryan Jones
Understanding Automatic Gain Control

Understanding Automatic Gain Control

How do designers cope with a system that has highly variable input amplitude yet requires fairly constant output amplitude? Let’s take a look.


Flash Freeze Photography with an Arduino

Flash Freeze Photography with an Arduino

Freeze moments in time to easily produce extraordinary close-up pictures with your digital camera, an Arduino, and these simple circuits.


Focusing on Phase: The All-Pass Filter

Focusing on Phase: The All-Pass Filter

How do you design a filter that (ideally) has the same gain for all frequencies? And, furthermore, why would you want to do this?


Build Your Own Low-Resistance Meter

Build Your Own Low-Resistance Meter

This project will show you how to make a device that can measure resistances as low as 0.1 ohms.


Projects Oct 26, 2016 by Robin Mitchell
Many Functions, One Tool: The Analog Discovery 2 from Digilent

Many Functions, One Tool: The Analog Discovery 2 from Digilent

An introduction to the Analog Discovery 2 by Digilent.


Build Your Own Metal Detector with an Arduino

Build Your Own Metal Detector with an Arduino

Building a metal detector using a Colpitts oscillator and an Arduino.


Projects Oct 03, 2016 by Evan Kale
Understanding Linear-Phase Filters

Understanding Linear-Phase Filters

Linear phase response, also known as constant group delay, is an important property in some filter applications.


Understanding Complex-Conjugate Poles in Filter Theory

Understanding Complex-Conjugate Poles in Filter Theory

This technical brief explains the importance of complex-conjugate poles and second-order stages in optimizing filter performance.


Understanding Quadrature Phase Shift Keying (QPSK) Modulation

Understanding Quadrature Phase Shift Keying (QPSK) Modulation

This technical brief covers the basic characteristics of a digital modulation scheme known as quadrature phase shift keying.


Understanding the Delta-Sigma ADC

Understanding the Delta-Sigma ADC

ADCs (analog-to-digital converters) can be described as either Nyquist-rate or oversampled converters. The Delta-Sigma ADC belongs to the oversampled family of converters. It relies upon oversampling and noise shaping to achieve high-resolution conversions.


The Actively Loaded MOSFET Differential Pair: Measuring Lambda, Predicting Gain

The Actively Loaded MOSFET Differential Pair: Measuring Lambda, Predicting Gain

In this article, we’ll look at the equation for differential gain and use LTspice to find the value of the channel-length-modulation parameter referred to as lambda (λ).


The Actively Loaded MOSFET Differential Pair: Output Resistance

The Actively Loaded MOSFET Differential Pair: Output Resistance

In this article, we’ll discuss MOSFET small-signal output resistance as we make our way toward predicting the gain of the actively loaded differential pair.


Advantages of the Actively Loaded MOSFET Differential Pair

Advantages of the Actively Loaded MOSFET Differential Pair

In this article, we’ll discuss two benefits of using an active load: improved biasing conditions and differential-to-single-ended conversion.


The MOSFET Differential Pair with Active Load

The MOSFET Differential Pair with Active Load

Learn about a fairly simple yet highly beneficial modification to the drain-resistor-based version of the MOSFET differential pair.


The Basic MOSFET Differential Pair

The Basic MOSFET Differential Pair

In this article, we’ll examine the most straightforward version of this foundational integrated-circuit amplifier topology.


Bridge Amplifiers for Single-Supply Applications

Bridge Amplifiers for Single-Supply Applications

This article describes the bridge-amplifier configuration and explains why it’s especially handy when you don’t have a negative voltage supply.


Inductor Out, Op-Amp In: An Introduction to Second-Order Active Filters

Inductor Out, Op-Amp In: An Introduction to Second-Order Active Filters

In this article, we’ll compare active and passive filters and look at some common second-order active topologies.


FIR Filter Design by Windowing: Concepts and the Rectangular Window

FIR Filter Design by Windowing: Concepts and the Rectangular Window

In this article, we'll review the basic concepts in digital filter design. We'll also briefly discuss the advantages of FIR filters over IIR designs, e.g. stability and linear-phase response. Finally, we'll go over an introduction to designing FIR filters via the window method.


Digital-to-Analog Conversion with the SAM4S Peripheral DMA Controller

Digital-to-Analog Conversion with the SAM4S Peripheral DMA Controller

Part Three in this three-article series shows you how to generate values for a discrete sinusoid and continuously convert this data into an analog signal without overburdening the CPU.


Projects May 09, 2016 by Robert Keim