App note: Load switches for mobile and computing applications

App note from Nexperia presenting simple load switches in mobile and computing applications. Link here (PDF) There are several reasons why a circuit or subsystem is required to be disconnected from the power supply using a load switch. A very simple and very common reason is that it helps saving power. An unpowered subsystem can […]

App note: Driving solenoids in automotive applications

App note from Nexperia about various solenoid driver used in automotive. Link here (PDF) There are a wide variety of solenoid drive circuit topologies. Most of them use MOSFETs in various configurations and driving modes. In this application note four of them will be discussed: solenoid driver with free-wheeling diode, solenoid driver with MOSFET avalanching, […]

App note: Power Battery Charger Calibration Fixture

Automated battery charger calibration fixture using Holtek’s ASSP MCUs. Link here (PDF) Power chargers for electric bicycles, electric motorcycles and power tools, etc., are all calibrated before delivery, thereby correcting any charging parameter drifts due to external component tolerances. This will ensure the output voltage and current conform to their specifications. However, traditional applications are […]

App note: BA45F55xx with power line transceiver

App note from Holtek on power line transceiver found on their BA45F55xx MCU. Link here (PDF) A Power Line Transceiver is a fire protection dual-line bus which is used as a data transceiver. The master gives a command to the slave using a voltage signal modulation method while the slave responds to the master using […]

App note: Op amps for MEMS Microphone preamp circuits

App note from TDK on design considerations of preamps used on MEMS microphones. Link here A microphone preamp circuit is used to amplify a microphone’s output signal to match the input level of the devices following it in the signal chain. Matching the peaks of the microphone’s signal level to the full-scale input voltage of […]

App note: Analog and digital MEMS microphone design considerations

App note from TDK about the things to consider when integrating analog and digital MEMS microphones into a system design. Link here (PDF) Microphones are transducers that convert acoustic pressure waves to electrical signals. Sensors have become more integrated with other components in the audio signal chain, and MEMS technology is enabling microphones to be […]

App note: Driving electronic paper displays (E-paper)

Silicon Labs’ app note on driving E-paper with their EFM32 micro. Link here (PDF) Electronic Paper Displays (EPDs) are types of displays that are reflective and bistable. Reflective in this case means that they rely solely on ambient light and does not use a backlight. Bistable is the property of retaining an image even when […]

App note: Designing with an inverted-F 2.4 GHz PCB antenna

PCB design guide for an inverted-F 2.4 GHz antenna from Silicon Labs. Link here (PDF) One of the main reasons to use a PCB antenna is to reduce cost. Since the antennas are printed directly on the board, they are generally considered to be free. On boards with room to spare, this will be true. […]

App note: Secure hash algorithms back to basics

Maxim Integrated’s introduction to SHA security. Link here (PDF) This application note goes over the basics of Secure Hash Algorithms (SHA) and discusses the variants of the algorithm. It then briefly touches on how the algorithm is used for authentication, including the concept of a Hashed Message Authentication Code (HMAC). It concludes by looking at […]

App note: Optocouplers in on-board chargers and battery monitoring systems

App note from Vishay on how optocouplers play a role on safety for Electric vehicles. Link here (PDF) The number of electric vehicles on the roads is steadily growing, increasing the need for safe and reliable battery systems and high efficiency battery chargers. Modern electric vehicles use battery systems with voltages up to 1000 V […]

App note: Control solution using logic, analog switches, and discrete semiconductor devices for reversing a one-phase motor

App note from Littelfuse on solution to control split-phase motor using logic devices and triacs. Link here (PDF) In the huge variety of the AC motors, one-phase motors are an excellent option when only the single-phase power is available to supply electrical energy which motors require to operate. One of the most common single-phase motors […]

App note: Circuit protection solution for lithium cells

App note from Littelfuse on PolySwitch PPTC for lithium cells protection. Link here (PDF) Primary lithium cells (i.e., AA and 2/3A) and rechargeable lithium cells (i.e., 18650, 17500, and prismatic) are used in many portable electronics applications, such as laptop or notebook computers. Their popularity is based on the fact that they offer high energy […]

App note: How to determine if an eFuse system can be safely hot−plugged

This app note from ON Semiconductors linked here (PDF) System designers must account for voltage surges that occur when supplies or loads are connected. eFuses are integrated circuits with many features to protect loads from these surges. However, it is important to ensure that the eFuse itself will not receive excessive voltage on its input. […]

App note: Analysis of power dissipation and thermal considerations for high voltage gate drivers

App note from ON Semiconductors on ways to dissipate thermals or reduce junction temperature of HVIC. Link here (PDF) Gate drivers used to switch MOSFETs and IGBTs at high frequencies can dissipate significant amount of power depending on the operating conditions. It is important to determine the driver power dissipation and the resulting junction temperature […]

App note: Termination recommendations for single-ended oscillator driving single or multiple Loads

Proper clock signal terminations app note from SiTime. Link here (PDF) Clock signals with fast edges see traces on Printed Circuit Boards (PCB) as transmission lines rather than simple wire connections. If the length of PCB trace exceeds certain limit it requires matching of the trace impedance to one or both of the source and […]

App note: Interfacing an STM32L1xx microcontroller with an external I2S audio codec to play audio files

I2S protocol interfacing with an STM32 microcontroller app note from ST Microelectronics. Link here (PDF) The I2S protocol is widely used to transfer audio data from a microcontroller/DSP to an audio codec in order to play melodies (stored in a memory) or, to capture analog sound (from a microphone). The STM32L1xx allows I2S audio communication […]

App note: Is the lowest forward voltage drop of real schottky diodes always the best choice?

App note from IXYS about the pros and cons of different forward voltage drop of real shottky diodes. Link here (PDF) According to the thermionic emission model, pure Schottky barriers exhibit a forward voltage drop, which decreases linearly as the barrier height diminishes; whereas the reverse current increases exponentially as the barrier height decreases. Consequently, […]

App note: Voltage vs. output speed vs. torque on DC motors

App note from Precision Microdrives about DC motor capabilities and their uses. Link here Why Change Torque? The most obvious benefit of varying the torque is to maintain a constant speed when the motor’s load varies, keeping in mind the interdependent nature of speed, torque, and voltage. Although this example may be outdated, audio cassettes […]

App note: TQFN package thermal pad via design guide

TQFN footprint pad via design guide for proper thermals from Diodes Incorporated. Link here (PDF) TQFN packages have exposed pads to provide excellent electrical grounding paths to the PCB and transfer the device heat through thermal vias on the PCB thermal landing to the internal copper planes. In order to maximize the removal of heat […]

App note: Understanding thermal resistance in the real world

App note from Diodes Incorporated about thermal resistance and how to manage them in real world scenario. Link here (PDF) There can be significant differences between the thermal characteristics stated on a device datasheet and what actually happens in a realworld application. Semiconductor manufacturers usually provide thermal resistance values for Junction to Case (RθJC) and […]