App note: USB Mass storage class on an Embedded Host

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Microchip’s application note (PDF!) on USB Embedded Host Mass Storage class:

With the introduction of Microchip’s microcontrollers with the USB OTG peripheral, microcontroller applications can easily support USB Embedded Host functionality. One of the most common uses of this capability is to interface to mass storage devices, such as USB Flash Drives and memory card readers. These devices utilize the USB Mass Storage Class.

App note: Thermal behavior of small-signal discretes on multilayer PCBs


App note from NXP Semiconductors about multilayer PCB as additional heatsink for flat SMD components mostly power transistors to dissipate heat. Link here (PDF)

This application note illustrates how to improve the power dissipation of discrete components by using multilayer PCBs. It focuses on the impact of using larger copper areas to improve the thermal behavior of applications.

App note: Enhancing cellphone battery performance during GSM pulses through the use of a parallel supercapacitor


Low ESR and ESL supercapacitor paralleled to cellphone batteries can react more quickly to the demanding power required by GSM pulses. A great appnote read from AVX, link here (PDF)

With the constant addition of features and functionality, battery life and reliability are becoming increasingly vital to those who rely on their smartphones. The transmission signal requires quick pulses of current from the battery, potentially causing the instantaneous voltage of the battery to drop below the phone’s minimum voltage of operation. This may cause the power to the battery to be temporarily interrupted. A series of tests were performed on multiple battery chemistries to determine the beneficial effect of placing an AVX supercapacitor in parallel with the battery, to improve the life of the battery as well as the quality of power provided from it.

App note: QuickBoot method for FPGA design remote update


A QuickBoot method for FPGA design remote update application note (PDF!) from Xilinx:

This application note presents detailed descriptions of the QuickBoot method that are important for evaluating the QuickBoot solution and debugging implementation problems. Demonstration implementations of the QuickBoot method are provided for the KC705 evaluation board using the serial peripheral interface (SPI) flash or byte-wide peripheral interface (BPI) flash. See KC705 Board Demonstrations, page 33 to run the QuickBoot demonstrations on the KC705 evaluation board.

App note: High voltage adjustable power supplies



TI application note (PDF!) on high voltage adjustable power supplies:

An improved approach is shown in Figure 2. Here an LM329B 6.9V zener reference has been stacked in series
with the LM317’s internal reference. This both improves temperature stability, since the LM329B has a guaranteed TC of ±20 ppm/˚C, and improves regulation, because more loop gain is available from the LM317.
These techniques can be extended for higher output voltages and/or currents by either using better high voltage transistors or cascoding or paralleling (with appropriate emitter ballasting resistors) several transistors. The output short circuit current, determined by R3, must be within Q2’s safe area of operation so that secondary breakdown cannot occur.

App note: Projection with LED light sources


LEDs are now mostly used in light projection systems due to their low power requirements, long life and robustness. Here’s an app note from OSRAM for proper integrations on these projection LEDs. Link here (PDF)

This application note provides insights into the use of LED light sources for projection applications. An overview of LED projection systems and their benefits is presented, along with a summary of OSRAM Opto Semiconductors LEDs suitable for these applications. Finally, fundamental design issues related to the use of LEDs in projection modules are addressed.

App note: Potting protection for outdoor LED video walls and signs


LED signs and large LED video panels are always subjected to harsh environment resulting to corrosion to their pcb mountings, here’s an app note from OSRAM about potting these LED panels for protection. Link here (PDF)

This note provides basic information about the potting of flat SMT LEDs in video wall and signage applications. Thereby details on material in use, examples of suitable equipment and the process are presented and described. Additionally, the note gives a short intro into video walls with a typical setup, varying LED type system effects and general challenges. Finally, the results of selected environmental tests are presented, to demonstrate their impact and the aptitude of potting protection method.

App note: PointLED® – It’s nice to be different


New SMD LED design from OSRAM ideal for mounting on PCB holes for illumination. Link here (PDF)

This application note provides insight into the universally deployable and flexibly mountable light source of the PointLED® product family. A fundamental overview of the LED construction as well as the optical and electrical characteristics and performance of the LED are presented.

App note: How to handle a reed switch


Proper handling of reed switches to prolong operation and or storage, an application note from HSI sensing. Link here (PDF)

Reed switches consist of two or three metal reed contacts (blades) that are hermetically sealed inside a glass tube. This seal, while strong, may be damaged if proper handling is not used. HSI Sensing has years of experience handling reed switches and have identified several best practices.