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 […]
Author Archives: DP
Low-cost open source ventilator-ish device
Johnny made a low-cost ventilator-ish device, that is available on GitHub: In the event that COVID-19 hospitalizations exhaust the availability of FDA approved ventilators. This project documents the process of converting a low-cost CPAP (Continuous Positive Airway Pressure) blower into a rudimentary non-invasive pressure support ventilator that could help with breathing during respiratory distress. It’s […]
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 […]
FSK LDPC data mode
David writes: I’m developing an open source data mode using a FSK modem and powerful LDPC codes. The initial use case is the Open IP over UHF/VHF project, but it’s available in the FreeDV API as a general purpose mode for sending data over radio channels. Via Rowetel.
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 […]
ClockSquared Mini
Willem has been working on a tiny word clock, the Clocksquared Mini: Summer break is here, and with some time to spare I decided to challenge myself with a project that I call “Clocksquared Mini”. It is Clocksquared, but in a tiny wristwatch package. This gives rise to a major challenge, as everything has to […]
Designing a Memory/IO (ETA-3400) addon for the ET-3400 trainer
Dr. Scott Baker designed and built an ETA-3400 Memory/IO accessory for the vintage Heathkit ET-3400 trainer, that is available on GitHub: I’ve always wanted one of these Heathkit microprocessor trainers, and finally one caught my eye on eBay and I pulled the trigger. The basic interaction with the trainer is through the onboard keypad and […]
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 […]
App note: Processing instructions for mounting of through-hole LEDs
Do and don’ts when mounting through-holes LEDs, app note from Vishay. Link here (PDF) Through-hole LED cases usually consist of epoxy casting compounds with duroplastic properties. It is in the nature of things that optical semiconductor devices require transparent materials with the best possible optical features. Unlike standard IC mold compounds, which use reinforcing fillers […]
Nano sheet factory
Building a nano sheet machine @ Fablab RUC Sometimes even very expensive and well build equipment breaks. This recently happened to researcher Biljana Mojsoska, a chemist at Roskilde University. She was working with nano sheets, an anti-bacterial coating for medical surfaces, as her machine stopped working. The fact that such equipment can be so expensive […]
Thermocouple meter and datalogger
Thomas (LA3PNA) has designed and built a thermocouple meter, that is available on GitHub: I have designed a thermocouple meter for use for obtaining temperature readings from thermocouples. Its used together with the thermal chamber described elsewhere on this site. The design is done primarily as a programmable instrument, but it has a OLED display, […]
App note: New reliability assessment practices for Tantalum Polymer Capacitors
App note from KEMET on their new suggested testing for Tantalum polymer capacitors. Link here Tantalum polymer capacitors are expanding their market share in the commercial world because they offer superior electrical performance (primarily much lower ESR), have outstanding reliability, and display a more benign failure response than the incumbent MnO2-cathode tantalum capacitor technology. It […]
App note: Moving capacitors for mobile phones to the dashboard
This application note introduces polymer electrolytic technology, the electric performance of these parts, advantages relative to other capacitors, and how the commercial-grade product was improved to pass the stringent AEC-Q200 guidelines. KEMET app note link here Tantalum polymer capacitors are popular in many decoupling applications including high performance DC to DC converters. This created a […]
Connect a Commodore with thermal printer
Connect a thermal printer to vintage Commodore computers using the IEC bus @ smdprutser.nl Since a couple of months I have fascination for vintage computers like Commodore or Nintendo. I’m in the process restoring and pimping a Commodore SX64 and realized I did’t have a printer for it. After all it is an executive machine […]
App note: Paralleling linear regulators made easy
Various configuration of linear regulator for parallel operation discussed in this technical article from Analog Devices. Link here Linear regulators provide a simple, low noise solution for dc-dc regulation. However, at higher VIN-VOUT differentials the low efficiency and high power dissipation of linear regulators limits the amount of output current that can realistically be delivered. […]
App Note: Optimizing CAN node bit timing to accommodate digital isolator propagation delays
Adding robustness by digital isolation and compensating for propagation delays to CAN network presented in this technical article from Analog Devices. Link here (PDF) Controller area network (CAN), standardized under ISO 11898, is widely used in industrial and automotive applications. CAN protocols such as DeviceNet or CANOpen rely on the built-in error checking and differential […]
App note: Impedance characteristics of bypass capacitor
App note from ROHM Semiconductors about different type of bypass capacitors impedance and some tip when replacing them. Link here (PDF) There are various types of capacitors. If you select parts only based on their capacitance values, the requirements for bypass capacitors may not be satisfied, leading to malfunction of devices or nonconformity to standards. […]