Sample overcurrent detection circuit from Texas Instruments. Link here (PDF) This is a unidirectional current sensing solution generally referred to as overcurrent protection (OCP) that can provide an overcurrent alert signal to shut off a system for a threshold current and re-engage the system once the output drops below a desired voltage lower than the […]
Category Archives: app notes
App note: Active filtering in automotive audio applications
App note from Texas Instruments on isolating DC and high frequency noise in audio using their automotive op amps. Link here (PDF) Phone calls, emergency alerts, and music are just a few of the reasons that a high quality audio system is vital in automotive infotainment and clusters. Operational amplifiers (op amps) are one of […]
App note: Blood pressure monitor fundamentals and design
Application note from NXP on blood pressure monitor fundamentals using their medical oriented MCUs. Link here (PDF) Arterial pressure is defined as the hydrostatic pressure exerted by the blood over the arteries as a result of the heart left ventricle contraction. Systolic arterial pressure is the higher blood pressure reached by the arteries during systole […]
App note: How to eliminate over stress of MOSFET during start-up of flyback converter
App note from Richtek about their embedded soft-start function to eliminate MOSFET stress. Link here Switching Power Supply, compared to Linear Power Supply, is widely used due to its advantages, such as small size, light weight, high efficiency, etc. Flyback Converter, one of the switching power supply topologies, is most suitable for power supply systems […]
App note: Common mode filter inductor analysis
App note from Coilcraft on the design and construction of common mode filter inductor. Link here (PDF) Noise limits set by regulatory agencies make solutions to common mode EMI a necessary consideration in the manufacture and use of electronic equipment. Common mode filters are generally relied upon to suppress line conducted common mode interference. When […]
App note: How current and power relates to losses and temperature rise on inductors and transformers
Coilcraft’s app note on temperature rise due to losses on inductors and transformers. Link here (PDF) Core and winding losses in inductors and transformers cause a temperature rise whenever current flows through a winding. These losses are limited either by the allowed total loss for the application (power budget) or the maximum allowable temperature rise. […]
App note: How to use LEDs with supervisory ICs for undervoltage and overvoltage fault indicators
Another app note from MAXIM Integrated utilizing supervisory chip and LEDs to indicate voltage faults. Link here Traditionally, supervisory ICs have been used to monitor voltage rails for undervoltage faults (UV). When a supply rail falls below a set threshold, the system is held in reset using the reset output signal to the microcontroller to […]
App note: How a SIMO PMIC enhances power efficiency for wearable IoT designs
App note from MAXIM Integrated on very compact PMIC using only single inductor to drive three independent switching regulators. Link here Small form factor and minimal power loss are key criteria for internet of things (IoT) hardware, particularly wearables. Meeting these criteria typically involves some tradeoffs. For example, to meet a specific power consumption goal, […]
App note: HT66FB574 single colour independent light streamer USB keyboard
Another app note from Holtek this time about their HT66FB574, a USB keyboard device that can support single color LED streamer. Link here (PDF) The video gaming industry is seeing continual increasing demand for multi-feature keyboards. These can include features such as keys with an individual LED which can display different graphical effects along with […]
App note: HT66FB574/572 colour effect USB mouse
App note from Holtek on using their HT66FB574/572 to develop color effect mice. Link here (PDF) Demands from the video gaming industry for different types of gaming mouse continue to expand. Adding a large number of RGB LEDs to the mice can produce different colours and brightness changes creating a range of visual special effects. […]
App note: Power battery charger application guidelines
App note from Holtek on smart battery chargers. Link here (PDF) Battery chargers usually are products which transfer alternating currents to low voltage direct currents and which are widely applied in various rechargeable battery application fields. According to different applications, battery chargers can be divided into two types, namely digital chargers and power battery chargers. […]
App note: I/O emulated UART baud rate calibration
Software/bitbang method of baud rate calibration for micro without built-in UART, App note from Holtek. Link here (PDF) Not every HOLTEK MCU contains a Universal Asynchronous Receiver/Transmitter function, otherwise known as a UART. If this function is required, it can be emulated using software. However, the software accuracy will change according to the system frequency […]
App note: Minimizing light flicker in LED lighting applications
Another application notes from Richtek this time on LED lamps flickering. Link here Applying LEDs in offline retrofit lamps seems straightforward, but should be done with care to achieve similar light quality as the conventional lamp that the user is trying to replace. Light flicker is one of the aspects that need to be considered […]
App note: Li-ion battery and gauge introduction
Richtek app note for Li-ion battery definitions and gauge introduction. Link here SOC is defined as the status of available energy in the battery and usually expressed as percentages. Because the available energy change depends on different charging/discharging currents, temperatures and aging effects, the SOC could be defined more clearly as ASOC (Absolute State-Of-Charge) and […]
App note: Light guides
Light guide basics app note from OSRAM. Link here (PDF) Light Guides are used wherever the light of a light source should be distributed homogeneously over a particular area, when there is a spatial distance between light source and the area which is to be illuminated.
App note: LED diagnosis in automotive applications
App note from OSRAM about different approaches on LED string diagnostic in automotive. Link here (PDF) One requirement especially in automotive applications is the diagnosis of failures in functions and systems. Therefore light functions realized with LEDs like break light, daytime running light, low and high beam may require a diagnostics function. This application note […]
App note: Challenge and Response with 1-Wire® SHA Devices
Another app note from Maxim Integrated about challenge-response security on 1-wire devices. Link here (PDF) Challenge-response can be a secure way of protecting access to any privileged material if implemented correctly. In this document, many options for challenge-response access control are discussed but the most secure method given is presenting a different random challenge on […]
App note: Extending I2C communication distance with the DS28E17
App note from Maxim integrated about alternative method to extend I2C bus. Link here (PDF) Systems are increasingly requiring greater distances for I2C buses. This article explains how the DS28E17 can be used to extend the distance of I2C devices while decreasing cost.
App note: Recommendations to avoid short pulse width issues in HVIC gate driver applications
Application note from ON Semiconductors discussing possible abnormalities on High voltage gate driver when operating on short pulses. Link here (PDF) The High−Voltage Integrated Circuit (HVIC) gate driver family is designed to drive an N−channel MOSFET or IGBT up to 600 V. One of the most common methods to supply power to the high−side gate […]
App note: High voltage inverting buck reduces complexity and board space
App note from ON semiconductors about repurposing a buck converter to produce negative voltages. Link here (PDF) Applications in the electronics industry ranging from sensor−based designs to power amplifiers are periodically faced with the requirement to generate a negative voltage rail. Although many transformer−based designs, charge pumps and other methods have been used to meet […]