Circuit design *

In this article I will talk about my attempt to create flexible, compact and beautiful modular prototyping framework

The sound of rock music, in particular of hard rock and heavy metal, is largely based on a specially distorted guitar sound, for which electronic “distortion” devices, tube amplifiers in “overloaded” mode, computers with appropriate software and digital processors are used. increasingly using neural network algorithms.

The distorted sound of electric guitars began to gain popularity around the 1960s. Since that time, the sound of overloaded tube amplifiers, connected to powerful dedicated guitar speakers with large dedicated speakers, has been considered the benchmark in rock music. But tube amplifiers were relatively expensive and inconvenient to operate. Therefore, semiconductor distortion devices were developed.

At that time, the electrical circuitry of distortion devices was relatively simple and the signal output from their output only vaguely resembled the sound of an overloaded tube amplifier. Nevertheless, it was still somewhat similar to the “sound of a lamp” and this provided a powerful incentive for designers of analog semiconductor distortion circuits to continue their research, complicate circuits and propose new circuit solutions. The heyday of analog solid-state distortion was around 1995-2010. The most popular were electrical circuit diagrams like those shown in the figure below.

Hi everyone, a few months ago I got a Brother AX-25, and since then, I've been working on turning it into a computer. It uses an Arduino to scan the custom mechanical keyboard and control the typewriter, and a Raspberry Pi is connected to the Arduino over serial so I can log into it in headless mode.

Many people are familiar with the situation when there is no Internet, and a small dinosaur appears on the Google Chrome screen. Today we will tell you how to implement this game on the Cyclone IV FPGA board.

We are Yegor Blinov, Egor Kuziakov, and Inga Ezhova - the first-year students of Innopolis University. In our program, there was a course "Computer Architecture", where we had labs with FPGA boards Cyclone IV and MAX10. We were inspired by this equipment and decided to implement the project on one of the boards.

SEPIC-Ćuk split-rail converter can be used to make positive and negative supplies from a single input voltage for relatively well-matched loads like operational amplifiers.

Transient models are time consuming. Average models reduce modeling time drastically.

The PWM switch average models for current- and voltage-mode are described in details in Christophe Basso’s book “Switch-Mode Power Supplies, Second Edition: SPICE Simulations and Practical Designs”. Using of these models for SEPIC and Ćuk converters is also shown.

This text shows how to use the PWM switch average model to design a split-rail SEPIC-Ćuk converter.

Knowing parameters of small-signal control-to-output transfer functions makes it easier for engineers to design compensation networks of DC/DC converters. The equations for SEPIC can be found in different works and Application Notes, but there are differences. A work has been done to solve this problem.

Simplified design equations for SEPIC with Current Mode control (CM) in Continuous Conduction Mode (CCM) suitable for practical design of compensation networks are shown.

Protocol AXI4 was developed for High-bandwidth and low latency applications. It is designed to allow communication between master and slave devices. Master is typically a DMA or CPU and slaves are DRAM controllers, or other specific protocol controllers: UART, SPI, and others. Sometimes one component can implement multiple instances of this protocol. Usually, a prefix is used to differentiate between multiple AXI4 interfaces.

For example, Ethernet MAC can integrate DMA and slave interface used to command MAC. MAC can accept commands on the slave interface that contain data about the location of the next ethernet packet and MAC can start fetching this packet using the separate master interface instance.

This article was motivated by common design mistakes AXI4 designers make when they are designing their Digital IP. (Looking at you Xilinx)

On Ali, an interesting toy – an oscilloscope called DSO138 is sold for a very inexpensive price. It has already gained quite a lot of popularity among electronics lovers, but the parameters of this device, alas, allow it to be more or less fully used only for debugging very low-frequency circuits. Actually, it is not positioned as a tool, but rather as a DIY-kit for novice electronics engineers.

This "toy" oscilloscope is assembled on the STM32F103 microcontroller, and with a fairly competent circuit design of the digital part, the presence of a fairly decent 320X240-dot color display, and not the most rotten analog path, everything, alas, is ruined by very weak ADCs on board the 32F103. The claimed band of 200 kHz can be recognized as such only with a very large stretch. Yes, it will show the presence or absence of a signal with such a frequency, but it will not be possible to really look at something beyond this.

At the same time, the 103-series has a slightly more powerful brother - the STM32F303, it is almost completely compatible with the legs, but it is significantly better in terms of the parameters we are interested in, there are 4 ADCs on board with a conversion frequency of 5 MHz (6 MHz with a 10-bit resolution). In this scenario, if you use all 4 ADCs in parallel with a 10-bit resolution, you can get a effective resolution of up to an honest 24 MSPS (millions of samples per second). The microcontroller is also inexpensive; you can easily find it on the same Ali for very reasonable money again. It is clear that the idea to change the microcontroller arose almost immediately after I tried this DSO138.

At the same time, if upgraded the toy can turn out to be a completely full-fledged tool that even professionals, not just novice amateurs, could already use. With these thoughts in mind, I decided to try to do something with a Chinese toy in my free time.

Space exploration was always fascinating, and recent developments have reignited the interest to the heights never seen since the last man stood on the Moon. People argue about Mars exploration and features of spaceships as their grandparents would’ve done if the internet existed fifty years ago. I’m an electronics engineer working in the aerospace industry, so I know a thing or two about the technical background of this stuff — and I see that these things aren’t common knowledge, and people often have significantly skewed ideas about the reasons behind many things and decisions. Namely, I’d love to speak of some misconceptions about radiation hardened integrated circuits and the means of protection from radiation-induced damage.