App note: Dual 1.4MHz buck regulator with USB ‘Dying Gasp’ support

This app note from Maxim describes how to build a USB powered circuit that will provide a short power-failure notice before losing power. This is called the “Dying Gasp” and it allows devices to preform a proper shut-down when USB power fails. A safe USB “dying gasp” shutdown requires a local energy storage capacitor to […]

App note: Pushbuttons Control Regulated Switching Converter

Here is an app note from Maxim describing how to implement a digital potentiometer to adjust the output of a boost converter. Digipot is controlled through two push buttons. One controls the direction of the wiper, while the other moves the digipot wiper in the selected direction. The digipot is implemented on the DC/DC boost […]

App note: Implementing bidirectional interface with a single common LED

Here is an app note from Mitsubishi Electric Research Laboratories describing how to implement short-range low-bandwidth bidirectional communication using common LEDs. It’s called LEDComm and requires only two pins of a microcontroller and a current limiting resistor to function. It works by making use of the fact that LEDs, once reverse biased, are also pretty […]

App note: 1000VA Digital pure sine UPS

Here’s a reference design from Microchip for a 1000VA pure sine uninterpretable uninterruptible power supply. UPS usually use 3 circuits to function. A charger for battery, a inverter to convert DC battery power to mains AC, and a controller that switches from mains to battery when the power is interrupted. This design utilizes a single […]

App note: Battery/charger load switch approximates ideal diode

Portable devices require a circuit that switches the power supply between battery and charger. This is usually done by using a diode on the battery line – when the charger is plugged in, the diode is reversely polarized and disconnects the battery from the rest of the circuit. This method however has drawbacks, namely power […]

App note: Acoustic thermometry

Orcinus tiped us about this interesting app note on acoustic thermometry from Linear Technology: People usually measure temperature in order to correct the distance determined using ultrasonic transducers. Acoustic thermometry takes the opposite approach – the distance is fixed and the time it takes for an acoustic pulse to make a round trip is used […]

App note: Layout and physical design guidelines for capacitive sensing

We think DIY capacitive touch sensing buttons, and sliders are cool. Designing and shaping your capacitive panels can be a pain. Here is an app note by Microchip that covers all the basics required to get your capacitive touch sensing project started. This app note starts with which pad shape and size is best suited […]

App note: Understanding switch-mode boost power stages

Boosting DC voltage is required in many applications, like LCD backlight, powering a 5v device with a battery and many more. This app note from Texas Instruments gives a detailed explanation on how it works and how to calculate all your components based on input/output specifications. The report includes detailed steady-stage and small-signal analysis of the boost power […]

App note: High speed USB design guidelines

This app note by Intel covers how to design for high speed USB. It’s full of great tips for your next project. While mainly written for multi-layer motherboard design, we picked up tips on proper termination and routing techniques. We picked up tips on routing and placement guidelines, trace length and spacing, proper termination, plane splits, […]