Category Archives: app notes

App note: Using thermistors in temperature tracking power supplies

Here’s a tutorial from Maxim describing thermistors and how to use them in temperature tracking power supplies. Thermistors are resistors whose resistance changes with temperature, increases with PTC type and decreases with NTC. This article provides a simple, intuitive tutorial on negative temperature coefficient (NTC) thermistors and how to make basic use of them in […]

App note: Energy harvesting applications with the LTC3588

Here’s a video from Linear Technology describing how to power microcontroller systems with Piezoelectric energy harvesting power supply IC LTC3588-1. It incorporates a full bridge rectifier, and a switch-mode regulator into one IC. New developments in ultralow power microcontrollers with their high level of integration are enabling monitoring systems which draw sub milliwatts of power. […]

App note: Similarities of Wave Behavior

Here is a video from the Bell Laboratories archives. It describes the similarities in wave behavior in all mediums, be it electric, sound, or mechanical. On an elementary conceptual level, this film reflects the multifaceted scientific hyperthinking that was typical of a Bell Labs approach. Host Dr. J.N. Shive’s presence as a lecturer is excellent […]

App note: Detecting human falls with 3-axis accelerometers

Here is an article from Analog Devices discussing the theory and application of detecting human falls with 3-axis accelerometers. While the article focuses on the ADXL345 3-axis accelerometers, the theory and principle behind it can be applied to other devices as well. This article, based on research into the principles of fall detection for an […]

App note: Matching MOSFET drivers to MOSFETs

Here’s an app note from Microchip detailing how to match MOSFET drivers to MOSFETs. There are many variations of MOSFETs out there, and matching one to your driver and vice-versa is essential to getting the most out of your system. This Application Note discusses the details of MOSFET driver power dissipation in relation to MOSFET […]

App note: DC to DC converter tutorial

Here’s a tutorial from Maxim on DC to DC converter design. Buck, boost, inverting and flyback topologies are covered. Diagrams, equations, and control techniques are available for these four common topologies. Switching power supplies offer higher efficiency than traditional linear power supplies. They can step-up, step-down, and invert. Some designs can isolate output voltage from […]

App note: Minimizing switching regulator residue in linear regulator outputs

Jim Williams from Linear Technology explains how to battle switching regulator residue in linear regulator outputs. If you want to clean up the switching regulator output by using a linear regulator, you’ll run into difficulties. Linear regulators are not very good at suppressing high frequency noise, and switching regulators output loads of it. The “secret […]

App note: Difference amplifier vs. current-sense amplifier for high side current measurement

Here’s an article from Analog Devices detailing the differences between current-sense amplifiers and difference amplifiers in high side current measurement. Current sense amplifiers offer measurement of the instantaneous current, while difference amplifiers offer average current measurements.  While current-sense amplifiers offer better current consumptions and lower noise, the difference amplifiers are more robust. Both types of […]

App note: Calculating power dissipation of MOSFETs used in high-power switching supplies

Here’s an app note from Maxim describing how to calculate power dissipation of MOSFETs used in high-power switching supplies. The article is focused on CPU power supplies which operate at lower voltages (0.9-1.75v) but require loads of current (+60A). This article provides step-by-step instructions for calculating the power dissipation of these MOSFETs and determining the […]

App note: Video playback and streaming with PIC32 microcontrollers

Here’s an application note from Microchip describing how to implement video playback, and streaming on PIC32 microcontrollers. The article is written around the Multimedia Expansion Board which features an LCD graphics controller, but it’s enough to grab the basic concepts for your own design. This application note describes four methods of playing a video file […]

App note: Transform a DC/DC converter into a full-featured battery charger

Here is an application note video from Linear Technology describing how to use their LTC4000 coupled with a switch mode regulator to charge batteries. This IC is a supervisory circuit that controls the feedback pin of a switching regulator. It provides the project with safe charging, and seamless switching from battery power to regulator power.

App note: Nine often overlooked specifications in analog to digital converters

Here’s an app note form Analog Design describing the nine often overlooked parameters of analog to digital converters, and how they impact the design. The article goes over the resolution, power supply rejection (PSR), common-Mode rejection (CMR), the clock slew rate, aperture jitter, aperture delay, conversion time and conversion latency, wake up time, output loading, […]

App note: Using UART to implement a 1-Wire bus master

Here’s an app note from Maxim describing how to implement a 1-Wire bus master using the UART peripheral of your preferred microcontroller. This application note explains how to use a microprocessor’s UART to implement a 1-Wire® bus master. It includes an explanation of the required electrical interface, UART configuration, and timing relationship between UART and […]

App note: Implement capacitive sensing on a PIC10F microcontroller

Here’s an app note from Microchip describing how to implement capacitive sensing using two pins on the tiny PIC10F microcontroller. Capacitive sensing is implemented by turning the comparator into a relaxation oscillator. The output of the comparator is used to charge and discharge the sensing capacitor, that is formed by a pad on the circuit […]

App note: Interview with Bob Dobkin the chief technical officer at Linear Technology

Here’s an interview with Bob Dobkin, the CTO and co-founder of Linear Technology. He talks about how he started in the industry, the founding of Linear Technology, reasons behind application notes, and how to become a good analog engineer. He also talks about Jim Williams, the late analog design guru who’s responsible for many excellent […]

App note: Eliminating audio system noise from HDTV

How HDTV systems impact audio noise, and how to limit it: Ensuring a pop and click free audio signal chain requires careful design on behalf of both the hardware engineer and software engineer. This article discusses how hardware system and software functionality issues cause pops and clicks and how engineers can prevent them

App note: Successful PCB grounding with mixed-signal chips

Here’s a tutorial from Maxim describing how to ground chips that use both analog and digital signals. The article goes into current path theory, and provides tips on how to improve your signal integrity in mixed signal devices. This tutorial discusses proper printed-circuit board (PCB) grounding for mixed-signal designs. Because these components govern the high-uptime […]

App note: Switching regulator power loss

Here’s a video from Linear Technology explaining why power loss is a more important factor than efficiency in switching regulators. Comparing the efficiency of two different switching regulators can be, and usually is ,misleading. Efficiency is a misleading number for comparison of switching regulators. The efficiency number can be manipulated by the input and output […]

App Note: Things to consider when designing a DC/DC power supply

Maxim covers some important things to consider when designing a DC/DC power supply. Topics include choosing the right DC-DC converter for the application; MOSFET gate capacitance; high switching frequencies and component size; equations and calculations; selecting peripheral components; component placement and trade-offs; grounding; load and line regulation; temperature sensitivity.