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 Although this example may be outdated, audio cassettes […]

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 […]

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. […]

App note: BA1117 dropout voltage

App note from ROHM Semiconductors about linear regulator dropout voltage. Link here (PDF) The dropout voltage is the difference between the input and output voltages that is necessary for the stabilizing operation of a linear regulator. When the input voltage approaches the output voltage, stabilizing operation cannot be maintained and the output starts dropping in […]

Supercapacitor uninterruptable power supply (UPS) for Raspberry Pi

smbakeryt built a couple supercapacitor uninterruptible power supply (UPS) prototypes for his raspberry pi projects: For my Convergent restoration, I decided to build an RASCSI to replace some failing SCSI hard drives. The RASCSI is a SCSI emulator built using a raspberry pi. Problem with these types of emulators is that if you carelessly power […]

Reverse-engineering the first FPGA chip, the XC2064

Ken has written an article on reverse engineering the first FPGA chip, the XC2064: The FPGA was invented by Ross Freeman1 who co-founded Xilinx2 in 1984 and introduced the first FPGA, the XC2064. 3 This FPGA is much simpler than modern FPGAs—it contains just 64 logic blocks, compared to thousands or millions in modern FPGAs—but […]

App note: RS-485 communication link vs. the electric fence, A demonstration of RS-485 EMC robustness

Analog Devices’ RS-485 robustness demonstration by direct application of HV transient to the communication line. Link here Industrial and instrumentation applications (I&I) require transmission of data between multiple systems, often over very long distances. The RS-485 bus standard is one of the most widely used physical layer bus designs in I&I applications. Applications for RS-485 […]