Application note from OSRAM on driving OLEDs with constant current for longer operation. Link here The operation of OLEDs with electronic drivers is similar to anorganic LEDs for the most part. In a majority of applications, standard LED drivers may be used also for OLEDs. Nevertheless, there are some important basic rules and OLED specific […]
Tag Archives: app note
App note: Current sensing power MOSFETs
SENSEFET App note from ON Semiconductors incorporate a current sense inside a power MOSFET, these devices are straight forward calculating for sense resistance and voltage but have trade-offs for smaller current sensing. Link here (PDF) Current sensing power MOSFETs provide a highly effective way of measuring load current in power conditioning circuits. Conceptually simple in […]
App note: Load switches: What are they, why do you need them and how do you choose the right one?
Application report from Texas Instruments on load switches to simplify power supply design. Link here (PDF) Integrated load switches are electronic relays that can be used to turn on and turn off power supply rails in systems. Load switches offer many other benefits to the system and can include protection features that are often difficult […]
App note: How to select the Triac, ACS, or ACST that fits your application
Choosing the right AC switch for your application based on specification like current rating, voltage rating and triggering quadrant. Here’s an app note from STMicroelectronics to guide you on selecting the right part. Link here (PDF) This document gives basic guidelines to select the AC switch device according to the targeted application requirements. These guidelines […]
App note: A logic-level transient-voltage protected AC switch
STMicroelectronics’ AC switch directly controlled by microcontroller. Link here (PDF) Home appliances such as washing machines, refrigerators and dishwashers employ a lot of low power loads such as valves, door lock systems, dispensers or drain pumps. Since these loads are powered by the mains in ON / OFF mode, they were initially controlled by relays. […]
App note: Low-power battery temperature monitoring
Low current consumption temperature battery monitoring TMP303 from Texas Instruments. Link here (PDF) Charging a battery cannot be independent of temperature. In fact, most batteries specify a range of temperatures where charging is permitted. Charging outside these bounds risks damage, failure or worse. To prevent charging when the temperature is too hot or too cold, […]
App note: Stopping reverse current flow in standard hot swap applications
Application report from Texas Instruments about a simple circuit that blocks reverse currents. Link here (PDF) The proposed circuit uses an inexpensive operational amplifier to sense the condition of the output voltage exceeding the input voltage, and subsequently disable the hot swap controller, stopping the flow of reverse current (current flow from the output (load) […]
App note: Fast Rail-to-Rail operational amplifiers ease design constraints in low voltage high speed systems
Migration to lower rail voltages considerations on operational amplifier designs an Application note from Analog Devices. Link here (PDF) Movement towards lower power supply voltages is driven by the demand that systems consume less and less power coupled with the desire to reduce the number of power supply voltages in the system. Lowering power supply […]
App note: Resolution enhancements of digital potentiometers with multiple devices
An old application note from Analog Devices about configuring multiple digital potentiometers to improve resolution, accuracy and programming complexity might add-up to the mix though. Link here (PDF) Digital potentiometers usually come with standard resistance values of 10k, 100k, and 1MW at a given number of adjustable steps. If an application requires a resistance range […]
App note: Selecting coupled inductors for SEPIC applications
Application example from Coilcraft on how coupled inductors gain advantage over separately wound inductors, calculations included. Link here (PDF) The SEPIC (Single-Ended Primary Inductance Converter) topology is used in applications that require characteristics of both a buck and a boost regulator, specifically the ability to step up and step down the input voltage. Most often […]
App note: Choosing inductors for energy efficient power applications
Designing efficient power converters guide from Coilcraft. Link here (PDF) In high frequency DC-DC converters, inductors filter out the AC ripple current superimposed on the DC output. Whether the converter steps the voltage down – buck – or steps the voltage up – boost – or both up and down – SEPIC, the inductor smooths […]
App note: ASIC fixes for noisy analog “Oops”
App note from Maxim Integrated about simple fixes that can solve most issues when designing with ASICs. Link here (PDF) Noise is a common problem in mixed-signal ASICs, degrading performance and jeopardizing the completion of products. This application note gives hints and tips for adding external circuits that make many of these ASICs operational for […]
App note: Multiplex boosted class-D without additional external circuitry
An analog switch MAX14689 from MAXIM Integrated let signals that are higher than rail voltage pass. Link here (PDF) Boosted class-D amplifiers drive speakers with voltages greater than the supply voltage. These amplifiers are becoming more common because they allow higher performance audio from a single lithium ion battery. Most boosted class-D amplifiers, however, do […]
App note: HT45F3420 LED flashlight application
Holtek’s HT45F3420 MCU provide LED flashlight application all in with minimal external components. Link here (PDF) In traditional LED flashlight application circuits, the battery is used to directly drive the LED which will cause uneven brightness levels and the possibility of damaged LEDs due to changing battery conditions. Using the HT45F3420 for LED flash application, […]
App note: BH45F0031 Earphone jack communication
Holtek’s App note about their audio to digital signal converter chip BH45F0031 that together with an phone app, communication via audio phone jack is possible. Link here (PDF) The BH45F0031 is a Flash type 8-bit high performance RISC architecture microcontroller, which is designed for smart phone headset interface applications that can directly transmit data and […]
App note: Charging batteries using USB power
Fairly old application note from MAXIM Integrated about getting out power from USB ports. Link here (PDF) Many devices with rechargeable batteries use USB power to recharge the batteries while they are connected. This application note describes the power available from USB and how it can be used to charge batteries, including circuits and some […]
App note: Improve flicker performance of direct AC driven LED fixtures with self valley fill
Application note from ON Semiconductors on LED lighting flicker caused by its own AC supply by adding an improved self valley fill circuit. Link here (PDF) To provide power to LED loads from AC input, SwitchMode Power Supplies (SMPS) are generally used since LED need to be driven by regulated current. Consequently, LED lighting solution […]
App note: Using touch interface in harsh environments
Tough design and software reference from NXP of touch interface. Link here (PDF) The touch-sensing method is used to replace most of traditional tact switch inputs as a new type of human-machine interface used in home-appliance applications. However, using such kind of detection method in harsh environment is still a challenge for most of product […]
App note: Water level monitoring
A reference design from NXP about water level detection using pressure sensor. Link here (PDF) Many washing machines, even the ones using the best cleaner for washing machine, that are currently in production, use a mechanical sensor for water level detection. Mechanical sensors work with discrete trip points enabling water level detection only at those […]
App note: Choose the right voltage regulator to extend battery life in wearables
App note from Maxim Integrated on wearable devices demanding reduced quiescent and shut down currents when in idle and in sleep mode in a voltage regulator. Link here Wearable devices have emerged as the next big market opportunity in the electronics industry. Smart watches are among the most popular wearable items today. The healthcare market, […]