A while ago we heard about some new PIC microcontrollers with a tiny bit of integrated logic, a CPLD-lite that can replace a few external logic chips. This app note shows how to make a button debouncer with the peripheral. In this application note, a PIC10F322 is being used to implement a delay block/debouncer. The […]
Tag Archives: app note
App note: Guide to VFD operation
Here is an application note from Noritake Itron, a VFD tube manufacturer, explaining VFDs in detail. The article goes into the theory of operation, how it should be powered, how it should be driven, the timing characteristics, and more…
App note: Disposable metal boxes make excellent shielded enclosures
Believe it or not, Maxim dedicated a whole app note to describing the benefits of using disposable metal boxes as EMI shielded enclosures for your projects. Small steel tins some candy manufacturers use provide both electrical and magnetic shielding: One way to break this wasteful cycle is use the small steel tins in which candies […]
App note: Nixie tube data archive
Dieter’s nixie tube data archive contains loads of information about nixies. Theory of operation, control circuits, power supplies, and reference tables for common nixies – it’s all there.
App note: High power LED driver with PIC12F675
A current controlled buck converter for driving high-power LEDs. The PIC12F675 microcontroller has an integrated comparator, which in combination with a low pass filter provides a control circuit for the SMPS. The circuit is based on a buck topology switching power supply using the on-chip comparator peripheral within the PIC12F675 microcontroller. The switching power supply […]
App note: SEPIC-Ćuk Converter gives split rails from a single supply
Analog Devices describes the SEPIC-Ćuk Converter. This type of DC/DC converter is used to create two outputs with the same voltage, but different polarities. This is particularly useful for powering the two rails of op-amp based circuits. A better solution is a SEPIC-Ćuk converter. This topology consists of an unregulated Ćuk converter tied to the […]
App note: Tiny synchronous step-up converter design guide
Here is a design guide from Linear Technology describing how to design boost power supplies that can work from as little as 0.7 volts. These constant voltage power supplies that can run off until nearly every last drop of power is consumed.
App note: Reducing acoustic noise in PWM controlled fans
Microchip describes techniques to reduce acoustic noise in pulse width modulator controlled fans. One solution is to use an RC filter to decrease the slew-rate of the PWM pulses. Fan speed control extends fan service life and decreases airflow noise and average fan current. The most efficient way to implement fan speed control is to […]
App note: Comparing serial data protocols
This serial digital data network table compares 8 of the most popular serial communication protocols – 1-Wire, I2C, SMBus, SPI, MicroWire, M-Bus, CAN, and LIN.
App note: High-speed ADC Layout tips and tricks
Here is an article from Electronic design covering some interesting tips and tricks for high speed ADC layouts: There is no way to cover all the specifics when designing a high-speed, high-resolution converter layout. Each application is different and sometimes unique. However, these key points will be useful to designers in better understanding their future […]
App note: Power conversion, measurement and pulse circuit collection
Here is another circuit collection from Linear Technology. This one covers power conversion, measurement, and pulse circuits. This ink marks LTC’s eighth circuit collection publication. We are continually surprised, to the point of near mystifi cation, by these circuit amalgams seemingly limitless appeal. Reader requests ascend rapidly upon publication, remaining high for years, even decades.
App note: Switch mode regulators for battery powered systems
Maxim describes various SMPS regulator topologies for battery powered systems. Isolated and non-isolated topologies are covered: This tutorial presents an overview of regulator topologies for battery-powered equipment. The discussion covers linear regulators, charge pumps, buck and boost regulators, inverters, and flyback designs. The importance of peak current is explained, and schematics of each topology are […]
App note: Capacitive touch sensors with metal coverings
Usually capacitive touch interfaces can’t be used with metal coverings, but Microchip’s Metal Over Cap overcomes this limitation: As a user interface, capacitive touch has several advantages: it is low power, low cost, simple to implement, reliable mechanically, and it allows designers a great deal of freedom in the shape of the buttons. However, for all […]
App note: Theory behind ground loops
Analog Devices discusses ground loops and how to manage them: Transmitting data over long distances is fraught with potential problems. A ground loop can be a source of interference that can induce a noise voltage between the grounds on either end of the transmission. If this voltage is large enough, it can cause data errors […]
App note: Using and understanding voltage references
This tutorial on voltage references covers theory and how it works in practice: When specifying a reference, keep in mind that initial accuracy, temperature coefficient and long-term stability all play a role in overall accuracy of the finished product. By taking some care in applying the reference, and by avoiding some key pitfalls, the reference’s […]
App note: Circuits and principles of high side current measurement
Maxim describes several high side current measurement circuits: This application note describes the use of current sense amplifiers, differential amplifiers and instrumentation amplifiers to measure battery charge and discharge currents in portable equipment, computer notebooks and USB accessories. It compares high side current sense amplifiers with low side differential amplifiers and recommends selection criteria for […]
App note: IrDA stack for infrared data exchange
IrDA is a set of protocols for exchanging data over infrared light. It’s significantly more complicated at the protocol level and hardware level than simple IR transmitter like remote controls. To get started in IrDA you’ll need some software to encode and decode packets, Microchip describes their IrDA stack in this app note: The Microchip […]
App note: Understanding microphone sensitivity
Analog Devices discusses the sensitivity of analog and digital microphones. Sensitivity, the ratio of the analog output voltage or digital output value to the input pressure, is a key specification of any microphone. Mapping units in the acoustic domain to units in the electrical domain determines the magnitude of the microphone output signal, given a […]
App note: Ceramic input capacitors can cause overvoltage transients
This app note from Linear Technology describes why ceramic capacitors aren’t an ideal replacement for tantalum based caps. The higher internal inductance of ceramic capacitors creates high voltage spikes: Applying a voltage step to a ceramic capacitor causes a large current surge that stores energy in the inductances of the power leads. A large voltage […]
App note: Theory behind the CMOS analog switches
Maxim has a tutorial describing the theory behind CMOS analog switches, and tips for selecting the right ones for your projects. This tutorial presents the theoretical basis for analog switches and describes some common applications for them. The special features of calibration multiplexers (cal-muxes), fault-protected switches, and force-sense switches are discussed as well.