App note: How to measure the efficiency of a multiphase buck converter integrated circuit

Tips from Maxim Integrated on how to measure efficiency on complicated multiphase converters. Link here

Due to the nature of multiphase buck converters, perceived efficiency varies for a static operating condition depending on the load and output voltage measurement connections, as well as the symmetry of the PCB layout. An engineer evaluating multiphase buck converters should understand the nuance of efficiency measurement that this article explores, as well as PCB layout. How to fairly compare efficiency of multiphase buck converters on different evaluation boards needs to be addressed. This application note explores the underlying reasons and offers a method for measuring the most accurate efficiency in a multiphase buck converter.

App note: How to save power in high-precision measurements

App note from Maxim Integrated on achieving a lower power sensing in analog front end. Link here

In precision signal conditioning and measurement applications, a delta-sigma ADC has often been preferred over a SAR ADC on account of high-resolution output and highly integrated internal blocks such as a PGA or GPIO voltage reference. However, in some circumstances, the delta-sigma ADC’s high resolution is not needed or cannot be achieved, and its high-power consumption becomes a drawback.

App note: Flash analysis techniques and best practices

App note from Infineon on the basics of flash memories and their failure analysis recommendations. Link here (PDF)

Nonvolatile memory devices (like Flash) are often used in embedded applications that rely on the storage of system configuration, dynamic data, or both. This data needs to be retained during a power interrupt or power cycle. In case of a system malfunction, the reproducibility of the failure is influenced and depends on the state of the nonvolatile memory. This application note briefly explains the basic operation of Flash memory devices and recommends several analysis techniques.

App note: Designing with cypress quad SPI (QSPI) F-RAM™

App note from Infineon about quad SPI, an enhanced SPI protocol that provides four times data throughput at higher frequencies. Link here (PDF)

In order to manage the wide range of multimedia, graphics, and other data intensive content, embedded systems have evolved to offer more sophisticated features. These features place extra demands on the often-limited on-chip memory of the host controller (or MCU). External memories with parallel interface have long been used to extend the on-chip MCU’s storage limitations. Memories with a parallel address/data bus come in high pin-count packages and require more pins on the controller to communicate with.
The QSPI F-RAM supports single data rate (SDR) for all its SPI interface options up to 108 MHz, while it also supports the double data rate (DDR) up to 54 MHz but for specific opcodes. The 54-MHz DDR interface offers the same data throughput as the 108-MHz SDR but at half the frequency. Some systems preferably use DDR at reduced frequency than the high-speed SDR, which helps reducing the system core and I/O frequencies, thus system power without compromising the data throughput.

App note: Solid electrolytic capacitors designed for high temperature applications

New development and manufacturing process produces extended temperature endurance of solid capacitors discuss in this app note from KEMET. Link here (PDF)

For decades the maximum recommended operating temperature of solid electrolytic capacitors was 125°C. Responding to needs in the automotive and downhole drilling industries passive component manufacturers developed surface mount tantalum capacitors rated at 150°C in 2002-2003. Since that time the industry has introduced high temperature capable tantalum capacitors generally in 25°C increments roughly every four years. Today multiple manufacturers have products rated at 230°C poised for market release.

App note: Supercapacitor leakage current and self discharge characteristics

App note from KEMET about supercapacitor’s leakage and self discharge and their differences in order to take account the back-up time of an application. Link here (PDF)

Supercapacitor is widely used for RTC backup application to provide power to RTC circuit in electronics when the power source to the system is disconnected. Self-discharge characteristics is one of the important characteristics to determine the backup time. Self-discharge current is often confused with leakage current characteristic.

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.