App note: Pulse load handling for fixed linear resistors

Technical note from Vishay about linear resistor handling pulsed currents. Link here (PDF)

The power and thermal behavior of fixed linear resistors are mostly based on DC or RMS loads, but pulse loads, like single energy pulse or a continuous flow of pulses, become more and more an important factor in professional electronics.

App note: Using the Si72xx hall-effect magnetic position sensors

App note from Silicon Labs on their hall-effect Si72xx magnetic sensor to sense position, count revolution and security system seal tamper sensing. Link here (PDF)

These devices all measure magnetic field in the axis perpendicular to the package. All of these parts share the attributes of low power, high sensitivity, and low noise. The simplest parts in this family have a single output pin that goes high or low at a certain magnetic field. Options are available to output the magnetic field by I2C, SENT, PWM or analog format, to put the part in a very low power sleep state (disable pin), to turn on an on-chip test coil (BIST) and to indicate when a higher than expected field has been detected (tamper).

App note: PN7150 hardware design guide

A hardware design guide using NXP’s PN7150 full featured NFC controller. Link here (PDF)

This document is intended to provide an overview on how to integrate the NFC Controller PN7150 from hardware perspective.
It presents the different hardware design options offered by the IC and provides guidelines on how to select the most appropriate ones for a given implementation.
In particular, this document highlights the different chip power states and how to operate them in order to minimize the average NFC-related power consumption.

App note: Lowering audible noise in automotive applications with TI’s DRSS technology

Texas Instruments’ switching noise on audio reduction using spread spectrum tech. Link here

Automotive systems have many regulations and requirements, from electromagnetic interference (EMI) to thermals to functional safety, but one consideration that stands above the rest when it comes to immediate consumer dissatisfaction is audible noise. In this technical article, I’ll discuss common sources of audible noise, and how devices with TI’s dual random spread spectrum (DRSS) technology can help you eliminate audible noise in your designs.

App note: How to design an accurate DC power supply

Technical designs from Texas Instruments on accurate DC power supplies. Link here

Test and measurement applications like battery test, electrochemical impedance spectroscopy and semiconductor test require accurate current- and voltage-output DC power supplies. The current and voltage control accuracy of the equipment need to be better than ±0.02% of the full-scale range over a ±5°C ambient temperature change. The accuracy largely depends on temperature drift of the current-sense resistor and amplifiers. In this article, you will learn how different components affect system accuracy, and how to choose suitable components for a precision DC power-supply design.

App note: Terminations for advanced CMOS logic

App note from ON semiconductor on proper terminations when using advance CMOS logic to minimize power consumption. Link here (PDF)

Advanced CMOS logic such as ON Semiconductor’s FACT® logic, has extended CMOS performance to the level of advanced bipolar technologies. While high−performance design rules that are currently utilized for bipolar designs are also applicable to CMOS, power consumption becomes a new area of concern in high−performance system designs.
One advantage of using advanced CMOS logic is its low power consumption. However careless circuit design can increase power consumption, possibly by several orders of magnitude. A simple FACT gate typically consumes 625 W/MHz of power; at 10 MHz, this translates to 6.25 mW. A 50 W parallel termination on the line will use over 361 mW with a 50% duty cycle.

App note: Battery fuel gauge [Smart LiB Gauge] for 1-Cell Lithium-ion/Polymer with LC709204F

New app note from ON Semiconductor about thier LC709204F fuel gauge chip. Link here (PDF)

LC709204F is a Fuel Gauge for 1−Cell Lithium−ion/Polymer batteries. It is a part of our Smart LiB Gauge family of Fuel Gauges which measure the battery RSOC (Relative State Of Charge) using its unique algorithm called HG−CVR2. The HG−CVR2 algorithm provides accurate RSOC information even under unstable conditions (e.g. changes of battery; temperature, loading, aging and self−discharge).
This application note will explain how to initialize various parameters for the selected battery to start a higher accuracy gauging. Users can set various registers based on their application requirement using the notes, guidelines and examples given in this note. Sample program codes explained at the end of the note will provide various guideline on how this device communicates with the host side application processors.

App note: Industrial digital inputs with the MAX22191

App note from Maxim Integrated on their parasitically powered digital input interface chip which are used favorably on industrial applications. Link here

A digital input (DI) is a circuit designed to receive a binary signal transmitted from an industrial sensor and translate that input into a reliable logic signal for a programmable logic controller (PLC) or industrial controller. Common examples of industrial binary signals are pushbuttons and/or temperature or proximity threshold indicators. The MAX22191 parasitically powered DI circuit can monitor Type 1 and Type 3 sink and source binary input signals for PLC and industrial circuits.

App note: Designing a flyback converter with the MAX17291 micropower boost converter IC

App note from Maxim Integrated about designing isolated flyback converter using their micropower boost converter IC for auxiliary and industrial applications. Link here

Flyback converters are widely used in isolated DC/DC applications because of their relative simplicity and low costs compared to alternative isolated topologies. The RS485, isolated CAN transceivers, auxiliary power supplies, etc. are a few applications of the low-power flyback topology. A flyback converter can be designed using a MAX17291 boost converter with a 3.75kV isolation.

QTPy-knob: Simple USB knob w/ CircuitPython

A how-to on making a simple USB media knob using rotary encoder and Neopixel ring:

I like minimal solutions to problems. I was playing with a CircuitPython-enabled QT Py on a breadboard with and a rotary encoder and I ended up making a USB knob, like many others have done before. But I realized: waitaminute, I can literally just plug the encoder directly onto the QT Py…

More details on todbot blog. All design files are available in the qtpy-knob github repo.

Check out the video after the break.

Continue reading “QTPy-knob: Simple USB knob w/ CircuitPython”

App note: How to multiplex a 1-Wire master into numerous channels

App note from Maxim Integrated on using only one 1-wire master on multiple 1-wire channels. Link here

1-Wire® networks are originally designed for communication with a single 1-Wire master and numerous 1-Wire slaves on a single 1-Wire bus. Preferably, a linear topology, which contains insignificant stubs, is best for a 1-Wire network. However, a star topology, which contains long stubs, is often unavoidable, and makes it more difficult to determine the effective limitations. A method to eliminate these difficulties is to break up a star topology into numerous channels by using an analog multiplexer (mux). Advantages of using numerous channels include accelerating individual 1-Wire slave access time, improving network robustness, and mixing overdrive-only slaves with standard/overdrive slaves on different channels. These advantages can be gained while still having a single 1-Wire master.

App note: Detecting over-power scenarios using Maxim’s quad channel power monitors and voltage supervisors

App note from Maxim Integrated on their power monitoring and supervisory ICs. Link here

It is inevitable to have a voltage protection circuit and a power monitoring circuit in any advanced electronics application such as Tablets, Smartphones and Notebooks etc. Power monitors are generally used in all applications that require to measure average power through the critical rails. These Supervisory ICs do not report faults in over-power scenarios. However, for portable applications , it is very important to report overpower/energy faults and assert an output to the microcontroller to prevent the damage of rest of the circuitry. A circuit, comprising of power monitor IC (MAX34417) and Supervisory IC (MAX16143) provides a solution to report under-voltage, over-voltage as well as over-power scenarios.

App note: Using 1-wire for flexible electro-mechanical contact applications

1-wire solution from Maxim Integrated for electro-mechanical attachment. Link here

Adding electronic functionality to traditional nonelectronic peripherals and consumables is a common application requirement. This is typically driven by system requirements, including storage of calibration data, manufacturing information, or original equipment manufacturer (OEM) authentication of the peripheral, accessory, or consumable. In addition to selecting the proper IC feature set to provide security and memory for these applications, a reliable and cost-effective solution is needed to attach the IC to the peripheral and make an electro-mechanical connection between the peripheral and host system.

App note: How to improve ADC measurement accuracy with high input source impedance

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.

Raspberry Pi floppy controller board

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: dV/dt ratings for low voltage and high voltage power MOSFET

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: Reliability of the OSLON® Black Series family

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.