How to drive capacitive loads with op amps. Operational amplifiers that drive large capacitive loads can have problems like oscillation and peaking. This article describes how to anticipate and limit theses problems: Other problems include: reduced bandwidth, lower output slew rate, and higher power consumption. This application note explains why these problems occur, how to […]
Category Archives: app notes
App note: Calculating the error budget in precision DACs
How to chose a voltage reference and digital to analog converter chips to get the precision and stability you need: This application note focuses on Maxim’s 3-terminal voltage references and precision DACs. To design a system, one must first understand how the parts are specified and then how their performance characteristics interact. Voltage references and […]
App note: Voltage reference circuit collection
Here is a voltage reference circuit collection from Linear Technology. This is a 32 page article with a ton of reference designs and specifications for each. How to select passive components for best performance is also covered.
App note: Digital to analog interface fundamentals
Analog Devices describes the fundamentals of working with digital-to-analog converters: This tutorial outlines some important issues regarding DAC interface circuitry including the voltage reference, analog output, data input, and clock driver. Because ADCs require references and clocks also, most of the concepts presented in this tutorial regarding these subjects apply equally to ADCs.
App note: Op-amp based DIY linear voltage regulators
This is not really an app note, but more of a tutorial on DIY op-amp based linear regulators. The article describes the basics of op-amp regulator, and includes schematics and in-depth explanations of how the various circuits work. This article follows the history of a popular series of DIY linear regulators. Starting from initial concepts […]
App note: Theory of operation of linear regulators
Here is an app note from Texas Instruments describing the theory of operation of linear regulators. It goes on to explain and compare various topologies used in integrated linear voltage regulators. The explosive proliferation of battery powered equipment in the past decade has created unique requirements for a voltage regulator that cannot be met by […]
App note: USB Keyboard Demonstration
Here is an USB keyboard demonstration from Atmel. The document describes how to start, and design USB HID class keyboard applications on the STK525 starter kit.
App note: Add high voltage capability to current sense monitors
Here is an app note from Maxim describing how to add high voltage capability up to 300V for the MAX47X (which have been replaced by MAX407X) bidirectional current sense monitors. Since the MAX47X draw low current, a simple floating power supply can be used to power the device even at 300V. The circuit of Figure […]
App note: Using UART Auto-Baud detection on dsPIC30 digital signal processors
Here is a app note from Microchip describing how to implement the Auto-Baud detection for UART operation on dsPIC30 digital signal processors. This function is useful when the oscillator of the dsPIC is unknown and/or the baud rate is unknown. All current dsPIC30F devices have a UART peripheral with Auto Baud capability. The signal on […]
App note: Using Philipp springs to create touch keys
Here is an app note from Atmel describing how build DIY touch keys using Philipp springs (or any spring made from conductive material) and their qTouch ICs. This design allows PTH LEDs to be mounted inside the keys. The Philipp™ spring is a simple and cost-effective method of creating a touch key on a dielectric […]
App note: Implementing digital lock-in amplifiers using the dsPIC DSC
Here is an app note from Microchip describing how to use dsPIC digital signal processors to implement digital lock-in amplifiers. Lock-in amplifiers use phase-sensitive detection to measure the presence of small signals buried in large amounts of noise. By measuring the coherent system response from an incoming AC signal, the digital lock-in amplifier can detect […]
App note: A reference design for high-performance, low-lost weigh scales
Bearmos tipped us about this reference design from Analog Devices for high-performance, low cost weigh scales. The design uses load-cell, and a load-cell ADC AD7799. The trend in weigh scales towards higher accuracy and lower cost has produced an increased demand for high-performance analog signal processing at low cost. The scope of this requirement is […]
App note: Automatic current-limiting in hot-swap applications
Maxim describes how current limiting functions on their MAX5976 Hot-Swap IC. This chip is useful for hot-swap applications, it allows the safe insertion and removal of circuits while the power is applied. Because the MAX5976 and similar devices use a single resistor to set soft-start and overcurrent protection levels, simple changes to the basic application […]
App note: Identify surface mount part codes online
The SMD Codebook is a comprehensive internet database of the two and three letter codes used to mark small surface mount parts. This is an indispensable resource for repairing and reverse engineering SMD circuits. SMD devices are, by their very nature, too small to carry conventional semiconductor type numbers. Instead, a somewhat arbitrary coding system […]
App note: Introduction to Power Stage Controllers
Power Stage Controllers drive transistors in applications like DC to DC converters, power factor correcting circuits, motor drivers, etc. Atmel describes the basics of their PSC equipped AVRs: This application note is an introduction to the use of the Power Stage Controllers (PSC) available in some AVR microcontrollers. The object of this document is to […]
Linear Technology staff Scientist Jim Williams remembered
Drone followed up on our App note: Thermocouple measurement post: Yes, this app note is written by the venerable Jim Williams who passed away last year. Mr. Williams was the author of many famous application notes at both National Semiconductor (now owned by Texas Instruments) and Linear Technology Corp. (LTC). There is a very nice […]
App note: Selecting and testing 32kHz crystal oscillators
Atmel describes how to select and test 32.768 kHz quartz crystals [PDF!] for real-time clocks. The basic tips on layout apply to any microcontroller project, not just those with AVRs. This application note summarizes the crystal basics, PCB layout considerations, and how to test a crystal in your application. A crystal selection guide shows recommended […]
App note: Find the right battery for your project
Maxim describes how to select the batteries best suited to a specific project. The main performance metric for batteries is, of course, battery life. On the surface, this is a simple spec, but in truth it has many dimensions. These include the system’s load profile (how much of the time it spends using full load […]
App note: Frequently asked questions about chip capacitor cracking
TDK Components describes how to handle chip capacitors to avoid cracking. Multilayer ceramic capacitors are very brittle components, and can be damaged if proper care isn’t taken. Multilayer ceramic capacitors should be handled very carefully during mounting, soldering, and handling. Any damage incurred during these processes, no matter how small, can contribute to premature component […]
App note: Technical guide to surface mount resistors
Here is a technical guide to surface mount resistors from Panasonic. It covers the theory behind various resistor materials and the manufacturing processes. Tables illustrate specifications for different types of resistors, and explain the failure mechanisms for them. Fixed resistors are principal electronic components composed electronic circuit. They are developed with demands of various electronic […]