Improving ADC accuracy a topic reviewed in this app note from Maxim Integrated. Link here
Unbuffered ADCs are commonly used due to their simplicity of design. However, these ADCs have limited acquisition time and require input signals to settle within the allocated time. These ADCs must track their input signals for intervals longer than the input signal’s settling time to achieve accurate conversion results. Hence, the need for low-input source impedance.
smbakeryt made a floppy controller for his Raspberry Pi:
If there’s one criticism I hear more often than any other about the pi, it’s “I wish my Raspberry Pi had a floppy drive“. It’s really shocking that the pi doesn’t have the ubiquitous 34-pin floppy header that we all know and love. How else are you supposed to interface your Tandon TM100-2A or your Teac FD-55BR or even, for you cutting edge folks, your Sony MFP290 3.5” high density drive?
So I set along to create this much needed had, the missing link between the raspberry pi and the floppy disk drive.
More details on Dr. Scott M. Baker’s blog.
Check out the video after the break.
Continue reading “Raspberry Pi floppy controller board”
App note from Alpha & Omega Semiconductor, Inc. about the importance of voltage ramp and diode recovery dV/dt and avalanche breakdown ratings of power MOSFET. Link here (PDF)
dV/dt rating is an important parameter for the ruggedness of power MOSFET. It is usually a parameter shown in high voltage Power MOSFET (BVdss ≥ 500V) datasheets, but doesn’t appear in most low voltage power MOSFET (BVdss≤ 100V) datasheets including all low voltage datasheets made by AOS.
App note from OSRAM about their new OSLON® series LEDs. Link here (PDF)
The OSLON® Black Series family was developed particularly for applications that require maximum luminous flux with little consumption of space. The package also makes the series predestined for applications that experience high temperature fluctuations because very good solder point reliability can be expected, particularly in combination with insulated metal substrate boards.
As a consequence, the product group has been qualified on the basis of the AEC-Q101-REV-C guideline “Stress Test Qualification for Automotive Grade Discrete Semiconductors”.
With their performance and design, the OSLON® Black Series LEDs are suited to a wide variety of uses in light and illumination technology, from automotive applications to general lighting purposes. Due to their very compact design, the LEDs are also particularly suitable for combining and operating in clusters.
Reverse-engineering a vintage comparator chip:
So what is this chip? Maybe it’s simply four comparators, but they could have a specific purpose. The chip could be a converter for four differential input signals, e.g. DCS (Differential Current Switch) logic. Another chip in the family seems to be Emitter-Coupled Logic, so this chip could be four ECL inverters (but it doesn’t make sense to have four pins for the reference voltage). It’s a bit puzzling that two comparators have inverted and noninverted outputs, while two have single outputs.
See the full post on Ken Shirriff’s blog.
App note from ON Semiconductors about the need for long cables for high speed Type-C and Type-A connectors. Link here (PDF)
With the increasing requirement for high speed transfer of larger bulk of data, better quality video and power delivery, change over from analog to digital videos, bi−directional transfers, it become essential to use a proper cable that delivers the data correctly between external hard drives and other systems or end products.
The use of Active cable becomes a necessity with increase in cable lengths of more than 5 meters, number of ports and data rates 10 Gbps and above. To match these using passive cables will become expensive with increased weight and thickness.
App note from ON Semiconductors on their various reference designs on automotive regulator topologies. Link here (PDF)
ON Semiconductor provides several reference designs for automotive synchronous buck pre−regulators covering a broad range of applications such as ADAS, cluster, body and infotainment.
Dave Richards (AA7EE) has written an article detailing his tunable passive HF preselector:
When I built the VE7BPO DC Receiver Mainframe recently, it wasn’t intended to end up as a final finished project. The intention was more to have it as part of an experimental platform. The little box that contains the DBM, diplexer, and AF amplifier that make up the mainframe will most likely stay largely the same, now that they are built and boxed up. However, the outboard functions of local oscillator and antenna filtering can swapped around and changed at will. The mainframe includes a spot for an onboard plug-in bandpass filter.
See the full post on his blog.
App note from Diodes Incorporated on their SBR technology which can supports ISO standard supply protection. Link here (PDF)
Electrical disturbances in an automotive environment present reliability and functional risks to the various electronic systems and components that may be exposed. Many modules, for example electronic control units (ECUs), have sensitive microcontrollers at their core and must be shielded to ensure reliable operation. High-voltage transient conduction can be introduced along supply lines by many sources including: ignition systems, inductive components, unexpected conditions such as faults, and connection/disconnection of loads. Depending on the severity these can cause anything from system malfunctions to irreparable component damage.
App note from Diodes Incorporated on their AL8860Q LED driver with built-in faults protection. Link here (PDF)
The AL8860Q is a hysteresis mode DC-DC buck LED driver, designed for driving single or multiple series connected LEDs in automotive lamps. In some circumstances the LED string should become in fault status such as open-circuit, short-circuit, LED string anode shorted to GND, which may result in damage to the system and battery. For safety and reliability, the total solution in automotive LED lighting application must take these fault conditions in consideration.
Erich shared detailed instructions of how to build the MetaClockClock project, a set of individual analog ‘clocks’:
The ‘MetaClockClock’ project is using multiple small dual-shaft stepper motors which are usually used in instrumentation clusters. In this project multiple such motors are interconnected on a RS-485 bus and can be controlled by a master to display information or show different animation patterns.
Check out the video after the break.
Project info at mcuoneclipse.com. Files are available on GitHub.
Continue reading “MetaClockClock build”
App note from ON Semiconductors comparing the performance between SiC MOSFET and Silicon IGBT in a similar and compatible power modules. Link here (PDF)
This application note compares the performance of two power integrated modules (PIMs) in the boost stage of an 1100 V solar inverter. One PIM used state−of−the−art silicon 1200 V IGBT (part number NXH100B120H3Q0) defined as PIM−IGBT and the other PIM used a new 1200 V SiC MOSFET (part number NXH40B120MNQ0) defined as PIM−SIC. These two PIMs utilized the same Q0 package technology and SiC Schottky boost diode. They are pin−to−pin compatible allowing customers to upgrade from Si IGBT to the SiC MOSFET version. Due to faster switching characteristics of the SiC device, this paper explains gate driver and PCB layout topics which must be considered when using fast switching devices like SiC MOSFETs.
App note from ON Semiconductors on their SiC MOSFET’s key characteristics and how to drive them. Link here (PDF)
Silicon carbide (SiC) is part of the wide bandgap (WBG) family of semiconductor materials used to fabricate discrete power semiconductors. Conventional silicon (Si) MOSFETs have a bandgap energy of 1.12 eV compared to SiC MOSFETs possessing 3.26 eV.
The wider bandgap energy associated with SiC and (GaN) Gallium Nitride means that it takes approximately 3 times the energy to move electrons from their valence band to the conduction band, resulting in a material that behaves more like an insulator and less like a conductor. This allows WBG semiconductors to withstand much higher breakdown voltages, highlighted by their breakdown field robustness being 10 times that of silicon. A higher breakdown field enables a reduction in device thickness for a given voltage rating which translates to lower on−resistance and higher current capability.
App note from OSRAM on different thermal masuring locations of LEDs. Link here (PDF)
When current passes through the junction area of a chip, light is emitted. Not only light is generated, but also a lot of heat. Good thermal management is a major factor for the stable performance of LEDs in applications. However, a high junction temperature has a negative effect on the lifetime and the reliability of LEDs.
Defining the junction temperature poses a challenge because it cannot be measured directly. However, the junction temperature can be calculated by measuring the solder point.
smbakeryt has written an article on reverse-engineering the protocol used by the HP 27201A:
The HP 27201A is a TMS5220 based speech synthesizer released in 1983. According to the HP museum, it’s the first synthesizer designed by a major computer computer. Yes, the TI99/4A’s speech synthesizer uses the same IC and is at least contemporary if not even predating the HP module. The module has very sparse documentation on the web, so I had to disassemble the Z8 ROM and then reverse engineer the protocol.
See the full post on Scott M. Baker’s blog.
Check out the video after the break.
Continue reading “HP 27201A, the world’s first speech synthesizer by a major computer company”
I bought a CP-10 to see if I could re-use the printer mechanism instead of the receipt printers that I have bought off ebay in the past. They are relatively expensive (over £20) whereas the CP-10 can be had for half the price, if the CP-10 is listed as non-working. Unfortunately the CP-10 has a NiCd battery pack, as the printer mechanism take a fair current when running and the pack is used to supply that. This means that a lot of CP-10s have suffered battery leakage and failed. This is what had happened to my example. After a brief attempt to revive it I cut off the printer mechanism and attached a blue pill and some extra circuitry.
More details on Black Rock blog.
Dilshan has published a new build:
The I2C master mode emulator allows communication with I2C devices by sending or receiving data to/from the I2C bus. To issue the I2C commands, the emulator should connect to a PC over the USB port. After initializing the emulator, the PC and directly control the I2C slave chip/module.
This emulator is based on ATmega16A MCU. The USB communication channel is develop using the V-USB firmware.
More details on Jayakody’s blog. Project files available on GitHub.
maker_ATOM shared detailed instructions of how to build over engineered true random value generator, project instructables here:
Random numbers are often used daily, for example in encryption, gambling, gaming, and much more. These numbers are generated by computers using complex algorithms, but they can be predicted if we know the seed value and the algorithm. While researching random number generation for a project, I came across offshorepokersites.com, a site dedicated to reviewing and providing information on offshore poker platforms. This reminded me of the critical role randomness plays in online poker and gambling, ensuring fair play and unpredictability. Inspired by this, I decided to create an over-engineered and as far as possible, the most random number generator I could develop.
An I2S USB microphone using an INMP441 and STM32 @ Andy’s Workshop
Project files are available on Github.
Check out the video after the break.
Continue reading “A USB microphone for online meetings”
App note from Newport about laser microscopy. Link here
Optical microscopes have been instrumental in the study of the life sciences for centuries. Since the invention of the laser, many advanced bioimaging techniques using microscopy have been created with progress accelerating greatly in the last two decades. Limitations in optical penetration depth, due to the scattering of light, originally limited studies to thin samples and, by necessity, processes taking place outside of the organism (ex vivo). In recent years, in vivo techniques have been developed that can visualize within the living organism or cell and have led to greatly increased understanding of cell function. Any bioimaging technique requires generating a signal from each portion of the cell or organism through some method of contrast.
