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Tomi Engdahl says:
Linear doesn’t always mean linear as with the edge of a ruler. A so-called linear opto-coupler can deliver a surprise along those lines. (Pun intended)
http://arw.li/6186zDh4p
#EDN #OptoCoupler #IndustryInsights
Linear opto-couplers and the loop gain ‘booby trap’
https://www.edn.com/linear-opto-couplers-and-the-loop-gain-booby-trap/?utm_source=edn_facebook&utm_medium=social&utm_campaign=Articles
I decided to measure the opto-coupler’s transfer function in two ways
The “linear” nature of the opto-coupler is not to be taken too literally. The device’s transfer function doesn’t switch or anything like that, but the first derivative of the output versus the input, which is to say the slope of the output versus the input, varies versus where you place the device’s operating Q-point. The variability in the device I examined was nearly 19 dB.
That much gain variation could have a rompin’-stompin’ effect on a feedback loop’s overall transfer function, possibly pushing a marginally stable feedback loop into conditional instability.
Tomi Engdahl says:
Addressing the growing needs of fault detection in high-power systems
https://e2e.ti.com/blogs_/b/analogwire/posts/addressing-the-growing-needs-of-fault-detection-in-high-power-systems?HQS=asc-dcc-padc-amc23cxx_2q22-exexnl-ta-ElectronicDesign_0504-wwe_int&DCM=yes&dclid=CObTq-ijyvcCFRhAHgIdXSsCPA
Fault-detection mechanisms are a necessity in high-power industrial systems such as motor drives and solar inverters, as well as automotive systems including electric vehicle (EV) chargers, traction inverters, onboard chargers and DC/DC converters.
Fault detection involves current, voltage and temperature measurements to diagnose any AC power-line fluctuations, mechanical or electrical overloads within the system. Upon the detection of a fault event, the host microcontroller (MCU) performs protective actions such as turning off or modifying the switching characteristics of power transistors or tripping the circuit breakers.
In order to increase efficiency and reduce system size, designers are moving away from insulated-gate bipolar transistors (IGBTs) to wide-bandgap silicon carbide (SiC) and gallium nitride (GaN) switching transistors, which enable faster switching speeds (>100 kHz) with even shorter withstand times (<5 µs).
Protecting power switching transistors from fault conditions begins by detecting overcurrent conditions, using either shunt- or Hall-based solutions. While Hall-based solutions enable a single-module approach, they suffer from poor measurement accuracy, especially over temperature. Other considerations for selecting between shunt- or Hall-based solutions include the isolation specifications and the primary conductor resistance. The primary conductor resistance in a Hall-based solution could lead to the same amount of thermal dissipation as in a shunt-based solution, however, with improvements in shunt technology, shunts now come with much smaller resistances to minimize thermal dissipation, and offer very high accuracy over temperature and lifetime.
A shunt-based approach with an isolated amplifier offers high measurement accuracy for both fault detection and feedback control. The isolated amplifier provides either basic or reinforced isolation.
The isolated amplifier has a propagation delay of 2 to 3 µs, however. Depending on the latency requirements of overcurrent detection, an isolated amplifier-based method may not be fast enough.
Using isolated modulators
As shown in Figure 2, it is possible to use an isolated modulator for simultaneous overcurrent detection and feedback control. The isolated data output (DOUT) of an isolated modulator provides a digital bitstream of ones and zeros at a much higher frequency. The time average of this bitstream output is proportional to the analog input voltage, and digital filters inside the MCU reconstruct the measured signal. The MCU can have multiple digital filters running in parallel using the same bitstream output, with one of the digital filters configured for high-accuracy feedback control and another digital filter configured for low-latency overcurrent detection.
A shunt-based method with an isolated modulator offers even better measurement accuracy for both fault detection and feedback control than an isolated amplifier. The worst-case propagation delay for overcurrent detection can be as low as 1 µs.
The isolated comparator shown in Figure 4 provides a small, ultra-fast method for overcurrent detection by integrating the functions of a standard comparator and digital isolator. You can use an isolated amplifier or isolated modulator for feedback control.
Isolated comparators such as the AMC23C12 provide a cost-effective, small-size solution for fault detection. These devices have very low latency (<400 ns), which enables ultra-fast overcurrent detection
Tomi Engdahl says:
What’s the Difference Between Analog and Digital Circuits in PCB Design?
April 21, 2022
This article shares some useful design guidelines for analog and digital circuits. What are the differentiating factors that PCB designers need to know?
https://www.electronicdesign.com/technologies/analog/article/21238481/mermar-electronics-whats-the-difference-between-analog-and-digital-circuits-in-pcb-design?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220330054&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
Analog circuit design guidelines.
Digital circuit design guidelines.
Differences in the guidelines between the two.
Several products in the electronics industry require both analog and digital printed-circuit-board (PCB) designs. The design requirements for analog circuits and digital circuits vary and the PCB engineer must follow corresponding guidelines while designing the circuit board. The signal requirements and effects of interference are quite different in these circuits. It’s necessary to have a good understanding of the major differences between the two circuit designs while optimizing the PCB for better performance.
The signal value for a digital circuit is always binary, whereas the analog signal varies over a range of minimum to a maximum value. This provides a larger error margin in digital signal transmission, but the analog signals must be well-controlled during transmission and reception. Hence, designing an analog circuit may be comparatively difficult and needs a better understanding of the signal transmission.
Usually, the external signal received by a sensor is analog and it must be converted to a digital signal for processing. A typical application will be a hybrid circuit that involves both analog and digital circuitry. As a result, the layout design should be isolating the two sections to avoid interference.
Tomi Engdahl says:
The Fundamentals of Digital Potentiometers and How to Use Them
https://www.digikey.com/en/articles/the-fundamentals-of-digital-potentiometers?dclid=CMDA2cS30vcCFdhUGAodTE0PBQ
Mechanical potentiometers have been used by designers for decades in applications ranging from circuit trimming to volume control. However, they have their limitations: their wipers can wear out, they are susceptible to moisture ingress, and they can accidentally be moved off their set position. Further, as the world turns digital, designers need an alternative to meet requirements for more precise control and high reliability, along with flexibility to adjust values remotely via firmware.
Digital potentiometer ICs—often called digipots—solve these issues by bridging the digital domain and the analog resistor world. As an all-electronic, microcontroller-compatible component, digipots allow a processor and software to control, set, and vary their resistance value or voltage divider ratio.
They offer features and functions which mechanical devices cannot provide and are more rugged and reliable as they have no moving wiper. They cannot be deliberately tweaked or inadvertently adjusted, avoiding inexplicable performance changes. Applications include LED thermal stabilization, LED dimming, closed-loop gain control, audio volume adjustment, calibration, and Wheatstone bridge trims for sensors, controlling current sources, and tuning programmable analog filters, to cite just a few.
This article will provide a brief introduction to potentiometers and their evolution toward digipots. It will then use components from Analog Devices, Maxim Integrated, Microchip Technology, and Texas Instruments to explain digipot operation, basic and advanced configurations, and how they address circuit adjustment requirements. It will show how their functions, features, capabilities, and options can be used to simplify circuits, make circuits processor compatible, and reduce or even eliminate the need for bulky, less-reliable mechanical potentiometers.
Begin with potentiometer basics
The resistance seen by the circuit between either end contact and the adjustable wiper varies from zero ohms (nominal) to the full rating of the wire or film resistance as the wiper rotates and slides along the resistive element. Most potentiometers have a rotation range of about 270 to 300 degrees, with a typical mechanical resolution and repeatability of around 0.5% and 1% of full-scale value (between one part in 200 and 100, respectively).
Digipots: Potentiometers in IC form
The all-electronic digital potentiometer emulates the functionality of the electromechanical potentiometer but does so using an IC without moving parts. It accepts a digital code in one of several formats and establishes a corresponding resistance value. As such, it is sometimes referred to as a resistive digital-to-analog converter (RDAC).
The digipot uses standard CMOS IC technology and does not require special fabrication or handling. The size of a surface-mount digipot IC, typically 3 x 3 millimeters (mm) or less, is far smaller than a knob-adjusted potentiometer or even a small screwdriver-adjusted trimmer potentiometer (trimpot) and is handled just like any other surface mount technology (SMT) IC with respect to pc board production.
In principle, the digipot’s internal topology consists of a simple serial string of resistors with digitally addressable electronic switches between the wiper and these resistors. Using a digital command, the appropriate switch is turned on while others are turned off, thus establishing the desired wiper position. In practice, this topology has some drawbacks including a large number of resistors and switches required and a larger die size.
To minimize these concerns, vendors have devised clever alternative resistor and switch arrangements which reduce their numbers but produce the same effect. Each of these topologies results in small differences in how the digipot is ranged and its second-tier characteristics, but much of this is transparent to the user. For the remainder of this article, we’ll use the term potentiometer for the electromechanical device and digipot for the all-electronic one.
Digipots offered range of specifications, features
As with any component, there are top-tier parameters as well as secondary ones to consider when selecting a digipot. The top rank issues are nominal resistance value, resolution, and the type of digital interface, while considerations include tolerance and error sources, voltage range, bandwidth, and distortion.
• The required resistance value, often called end-to-end resistance, is determined by the design considerations of the circuit. Vendors offer resistances between 5 kilohms (kΩ) and 100 kΩ in a 1/2/5 sequence with some other intermediate values. Additionally, there are extended range units which go as low as 1 kΩ and as high as 1 megaohm (MΩ).
• Resolution defines how many discrete step or tap settings the digipot offers, ranging from 32 to 1024 steps to allow the designer to match the needs of the application. Keep in mind that even a mid-range 256 step (8-bit) digipot has higher resolution than a potentiometer.
• The digital interface between the microcontroller and the digipot is available in standard serial SPI and I2C formats, along with address pins so that multiple devices can be connected via a single bus. The microcontroller uses a simple data encoding scheme to indicate the desired resistance setting. A minimalist digipot such as the Texas Instruments TPL0501, a 256-tap digipot with SPI interface is a good fit where power dissipation and size are critical (Figure 4). It is available in space-saving 8 pin SOT-23 (1.50 mm × 1.50 mm) and 8 pin UQFN (1.63 mm × 2.90 mm) packages.
Tolerance for digipots may be an issue as it is typically between ±10 and ±20% of nominal value, which is acceptable in many ratiometric or closed-loop cases. However, it can be a critical parameter if the digipot is being matched to an external discrete resistor or a sensor in an open-loop application. For this reason, there are standard digipots with much tighter tolerance, as low as ±1%. Of course, as with all ICs, the temperature coefficient of resistance and associated temperature-related drift can also be a factor. Vendors specify this number in their datasheet so designers can assess its impact it via circuit models such as Spice. Other tight tolerance options are available and are discussed below.
Although not a concern in static applications such as calibration or bias-point setting, bandwidth, and distortion are issues in audio and related applications. The resistance path of a particular code, combined with the switch parasitics, pin, and board capacitances, creates a resistor-capacitor (RC) low-pass filter. Lower end-to-end resistor values yield a higher bandwidth, with bandwidths up to about 5 megahertz (MHz) for a 1 kΩ digipot, down to 5 kHz for a 1 MΩ unit.
The maximum voltage which the digipot can handle is also a consideration. Low-voltage digipots are available for operation with rails as low as +2.5 volts (or ±2.5 volts with a bipolar supply), while higher voltage ones such as the Microchip Technology MCP41HV31—a 50 kΩ, 128 tap, SPI interface device—can work with rails up to 36 volts (±18 volts).
Nonvolatile memory assists with power resets
Basic digipots have many virtues but have one inescapable weakness compared to potentiometers: they lose their setting after power is removed, and their power-on reset (POR) position is set by their design, usually at mid-range. Unfortunately, for many applications, that POR setting is unacceptable. Consider a calibration setting: once established, it should be retained until deliberately adjusted, despite removal of line power or battery replacement; further, in many applications, the “correct” setting was the one which was last used when power was removed.
Therefore, one of the remaining reasons for staying with potentiometers was that they do not lose their setting on power reset, but digipots have addressed this shortcoming. It was initially common design practice to have the system processor read back the digipot setting during operation, then reload that setting on power up. However, this created power-on glitches and was often unacceptable for system integrity and performance.
To address this concern, vendors added EEPROM-based nonvolatile memory (NVM) technology to digipots. With NVM, the digipots can retain their last programmed wiper position when the power supply is switched off, while one-time programmable (OTP) versions allow the designer to set the wiper’s power-on reset (POR) position to a pre-defined value.”
Tomi Engdahl says:
https://www.electronicdesign.com/technologies/analog/whitepaper/21178731/electronic-design-ideas-for-design-volume-3?utm_source=EG+ED+Auto+Electronics&utm_medium=email&utm_campaign=CPS220415028&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Cracks in the System: Thermomechanical Fatigue of Electronics
May 6, 2022
Multiphysics simulation software can aid design engineers in assessing the risk of fatigue failure for electronic components.
Kyle C. Koppenhoefer
https://www.electronicdesign.com/industrial-automation/article/21241106/altasim-technologies-cracks-in-the-system-thermomechanical-fatigue-of-electronics?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220505061&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
https://etn.fi/index.php/new-products/13555-dronet-pitaeae-suojata-emi-haeirioeiltae
Tomi Engdahl says:
High-Voltage Batteries Ahead! Proceed with Isolation!
May 10, 2022
TI is trying to transform the tightly wound cylindrical coils and mechanical switches of traditional relays into components that can fit inside a standard IC package.
https://www.electronicdesign.com/power-management/article/21241197/electronic-design-ti-isolation?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220505063&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
The End of the Full Bridge Rectifier? (Sorry ElectroBOOM)
https://www.youtube.com/watch?v=S0j4xOuRzD4
In this video we will be having a closer look at active rectifiers. For decades we have been using full bridge rectifiers to convert our mains AC voltage into a DC voltage that we can then step down to power all of our electronics devices. But the problem is that a full bridge rectifier consists of 4 diodes that come with a noticeable voltage drop and thus power losses. Because of that an active rectifier uses MOSFETs instead of diodes in order to decrease power losses. Does that makes sense? Let’s find out!
0:00 The Problem with Full Bridge Rectifiers (FBR)
1:27 Intro
2:09 How does an FBR work?
3:36 The Idea of the Active Rectifier
4:38 Active Rectifier Controller ICs
5:40 25V AC Comparison Test
6:45 DIY Active Rectifier
7:59 230V AC Power Supply Comparison Test
9:46 Verdict
Tomi Engdahl says:
Video SerDes Tech Boosts Resolution Over a Longer, Single Wire
May 12, 2022
Sponsored by Texas Instruments: Achieve higher resolution and transfer uncompressed video, power, and more over one wire using V3Link serializers/deserializers.
https://www.electronicdesign.com/tools/learning-resources/whitepaper/21240305/texas-instruments-video-serdes-tech-boosts-resolution-over-a-longer-single-wire?utm_source=EG+ED+Connected+Solutions&utm_medium=email&utm_campaign=CPS220510036&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
The uncompressed transmission of video data, control signals and power is heating up—and it’s not just with the promise of warmer weather. A wide range of applications, from endoscopy, a non-surgical procedure used to examine a person’s digestive tract, to factory automation, require that high-bandwidth data be transferred over several meters worth of cable.
That presents a challenge, not just because of the signal loss introduced with such a transmission channel, but also due to the introduction of electromagnetic-interference (EMI) or electromagnetic-compatibility (EMC) considerations common to medical or industrial applications. Such external noise sources could interfere with the cable as data passes to its destination.
Increasing the resolution of an imager in a system increases the amount of data it generates, data that must be transmitted, processed, and stored. Unfortunately, connecting an imager over a small-diameter wire or cable can add signal interference. Here, we’ll discuss a modern solution to this problem: V3Link SerDes pairs, which can enhance resolution and reduce system size in high-speed video applications.
V3Link technology acts as a bridge between protocol-based data interfaces, which require multiple signaling conductors to transfer high-bandwidth data. Supported data-interface standards include HDMI, LVDS, MIPI CSI-2, and MIPI DSI. These standards, however, are designed to transfer video only over short distances, which may include PCB traces.
V3Link devices support various cable types. Applications typically utilize either coaxial or twisted-pair cables to carry information between serializer and deserializer. Coaxial cables tend to have lower insertion-loss characteristics when compared with twisted-pair cables due to their electromagnetic construction. Twisted-pair cables are typically more immune to the effects of electromagnetic interference. Most V3Link devices can support either coax or twisted-pair configurations to ensure flexibility in various applications.
V3Link transfer works by combining input data into packets or frames to be transmitted serially at high speed. Payload data makes up the majority of the frame. This is the high-bandwidth portion of the data, which could be comprised of video pixel information, audio data, or other data types including radar, LiDAR, and more.
By utilizing a proprietary echo-cancellation technique, V3Link SerDes allows for full duplex communication over one physical conductor.
Using this simultaneous back-channel communication, I2C access and GPIO transfer can be enabled across in either forward or reverse directions. V3Link deserializers utilize multiple equalization techniques to recover high-frequency signal content and mitigate the effects of intersymbol interference (ISI), reflections, or external noise influence.
SerDes technology such as the V3Link TSER953 serializer and TDES960 and TDES954 deserializers work in tandem to transfer high-resolution video, control signals, and power simultaneously over a single thin wire. These devices help establish links between sensors and processors to aggregate clock, uncompressed video, control, power, and GPIO signals
In addition to facilitating the transfer of video data, control signals, and power over a single cable, V3Link devices include adaptive equalizer technology that can compensate for a loss of up to 21 dB at 2.1 GHz, enabling the use of very thin 28 to 32 American-wire-gauge (AWG) cables. The higher the AWG number, the thinner the cable and the higher the signal loss. The ability to transfer power and control signals on the same thin cable also minimizes the number of conductors.
At typical power dissipation of 250 mW on the sensor side, V3Link serializers consume very low power. As a result, the sensor and serializers can be integrated into very compact areas without the need for power and heat dissipation, which requires additional space.
Conclusion
V³Link is a high-speed bidirectional video SerDes technology that enables uncompressed transmission of video data, control signals, and power using a single wire. As a high-speed, uncompressed video-transport technology, V3Link aggregates video, clock, control, and peripheral data from cameras, radar, LiDAR, or time-of-flight sensors to an SoC over a single wire or cable up to 15 m. V3Link serializers and deserializers extend cable reach while maintaining image quality, reducing power consumption and improving system reliability.
Enhancing Resolution and
Reducing System Size in High
Speed Video Applications
https://www.ti.com/lit/wp/slyy215/slyy215.pdf?HQS=asc-hsd-fpdl-v3link-asset-whip-ElectronicDesign_05-wwe_int&ts=1652878003867
Tomi Engdahl says:
Reinforced, Isolated Window Comparator Features Adjustable Threshold
May 18, 2022
The rugged window comparator for higher-power industrial and related applications provides reinforced galvanic isolation, while offering fast response to faults.
https://www.electronicdesign.com/technologies/analog/article/21242127/electronic-design-reinforced-isolated-window-comparator-features-adjustable-threshold?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220517097&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Comparators are one of the basic building blocks of analog and mixed-signal designs, providing one small but critical function, as their name indicates. Their role is often to be a “simple” safety threshold switch and fault-alert source—“simple” only in the sense that they do so reliably with a minimum of support components (or any software that could crash).
Now, they’re increasingly expected to function in electrically noisy and environmentally difficult higher-voltage situations, where galvanic (ohmic) isolation is needed both for basic system performance as well as user safety.
Adding such isolation to the comparator itself is difficult. It requires more than just the basic electrical performance, but also must be designed, built, and tested to meet multiple stringent industry and government standards for voltage, ruggedness, and temperature performance.
To address this need, Texas Instruments developed the AMC23C12, a reinforced, isolated window comparator with a fast response time and open-drain output that the company maintains is an industry first (Fig. 1). Its input and output are separated by an isolation barrier certified to provide reinforced galvanic isolation of up to 5 kVRMS per DIN VDE V 0884-11 and UL1577, and it supports a working voltage of up to 1 kVPK. It’s also highly resistant to magnetic interference.
Applications include overcurrent or overvoltage detection in motor drives, frequency inverters, solar inverters, and high-power dc-dc converters—all areas where voltages and currents are high, as is user shock risk, and safety-related performance is assessed across multiple parameters.
The comparison window is centered around 0 V; therefore, the comparator trips if the absolute value of the input voltage exceeds the trip threshold value. This trip threshold is adjustable from 20 to 300 mV through a single external resistor, so the comparison window ranges from ±20 to ±300 mV.
When the voltage on the REF pin is above 550 mV, the negative comparator is disabled and only the positive comparator is functional. The reference voltage in this mode can be as high as 2.7 V (particularly useful for monitoring voltage supplies).
While it’s possible to build your own combination isolator/comparator, TI maintains the AMC23C12 provides these less-obvious benefits:
Reduces “solution size” by 50% due to integration of a wide-input-range, low-dropout regulator; a window comparator; and a precision voltage reference.
Enables use of smaller-size passive components, since the high worst-case trip threshold accuracy (better than 3%) reduces design margins.
Provides ultra-fast overcurrent and overvoltage detection for greater system protection due to the short response time of under 400 ns.
Eases reuse of the comparator across multiple designs due to use of a single external resistor to set the adjustable trip threshold.
Given the critical nature of many if its designs-ins, even users of components providing the basic functionality of a comparator benefit from comprehensive technical support
Further support comes via the AMC23C12EVM evaluation module (Fig. 2), which costs $49. In addition, a detailed 15-page User’s Guide provides connection and configuration information, bill of materials, PCB layout, and more.
For those who need to further investigate approaches to fault detection in high-power systems, a brief TI blog “Addressing the growing needs of fault detection in high-power systems” goes through various ways to use combinations of isolated barriers, comparators, and modulators to achieve these goals
Addressing the growing needs of fault detection in high-power systems
https://e2e.ti.com/blogs_/b/analogwire/posts/addressing-the-growing-needs-of-fault-detection-in-high-power-systems
Fault-detection mechanisms are a necessity in high-power industrial systems such as motor drives and solar inverters, as well as automotive systems including electric vehicle (EV) chargers, traction inverters, onboard chargers and DC/DC converters.
Fault detection involves current, voltage and temperature measurements to diagnose any AC power-line fluctuations, mechanical or electrical overloads within the system. Upon the detection of a fault event, the host microcontroller (MCU) performs protective actions such as turning off or modifying the switching characteristics of power transistors or tripping the circuit breakers.
Protecting power switching transistors from fault conditions begins by detecting overcurrent conditions, using either shunt- or Hall-based solutions. While Hall-based solutions enable a single-module approach, they suffer from poor measurement accuracy, especially over temperature. Other considerations for selecting between shunt- or Hall-based solutions include the isolation specifications and the primary conductor resistance. The primary conductor resistance in a Hall-based solution could lead to the same amount of thermal dissipation as in a shunt-based solution, however, with improvements in shunt technology, shunts now come with much smaller resistances to minimize thermal dissipation, and offer very high accuracy over temperature and lifetime.
Tomi Engdahl says:
Knock Out System Noise with Ultra-Low-Noise LDO Regulators
May 23, 2022
Sponsored by Texas Instruments: Ultra-sensitive applications require a “clean” dc power supply and that typically means integrating low-noise, low-dropout regulators in their designs.
https://www.electronicdesign.com/resources/whitepaper/21241859/texas-instruments-knock-out-system-noise-with-ultralownoise-ldo-regulators?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220519042&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
All You Need To Know About MOSFETS To Fix Stuff! How Mosfets Work Fail Test In & Out of Circuit
https://www.youtube.com/watch?v=LNu00nMBaaQ
Tomi Engdahl says:
Overcome the Challenges of Using Sub-Milliohm SMD Chip Resistors (Part 2)
May 23, 2022
Treating sub-milliohm chips as a separate class of component is a smart strategy that helps solve associated design challenges. Part 2 of this series features strategies for verification of the ohmic value of unmounted components and critical assembly.
https://www.electronicdesign.com/technologies/analog/article/21242473/tt-electronics-overcome-the-challenges-of-using-submilliohm-smd-chip-resistors-part-2?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220524015&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
E-Mode GaN Transistor Works Like Silicon MOSFET for Easier Design-In
May 25, 2022
A spin-out of Cambridge University, Cambridge GaN Devices is a fabless semiconductor company that develops a range of energy-efficient enhancement-mode GaN-based power devices.
https://www.electronicdesign.com/power-management/video/21242637/electronic-design-emode-gan-transistor-works-like-a-silicon-mosfet-for-easier-designin?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220523009&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Cambridge GaN Devices (CGD), a spin-out of Cambridge University, is a fabless semiconductor company that develops a range of energy-efficient, enhancement-mode GaN-based power devices.CGD introduced ICeGaN, presented as the first enhancement-mode GaN transistor that can be operated like a silicon MOSFET without the need for special gate drivers, driving circuitry, or unique gate-voltage-clamping mechanisms.
Tomi Engdahl says:
Three Compact Solutions for High Step-Down Voltage Ratios
May 25, 2022
The article explains why the non-isolated buck converter faces challenges to downconverting high dc input voltage to low output voltage at high output current, and presents three approaches for downconverting such steep voltage ratios.
https://www.electronicdesign.com/power-management/whitepaper/21242648/analog-devices-three-compact-solutions-for-high-stepdown-voltage-ratios?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220523009&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Designing a low EMI power supply
Explore this comprehensive training series to learn more about the fundamentals of EMI, the various technologies that can help reduce emissions and more
https://training.ti.com/designing-low-emi-power-supply?HQS=app-null-null-pwrbrand_lowemi_pbj_lowemipowersupply-asset-tr-ElectronicDesign_emi_layer1-wwe&DCM=yes&dclid=CK7s3__3_vcCFRKfGQod0IsKpA
Texas Instruments 1 AAJ 3Q 2016
AutomotiveAnalog Applications Journal
Reduce buck-converter EMI and voltage
stress by minimizing inductive parasitics
https://www.ti.com/lit/an/slyt682/slyt682.pdf?HQS=app-null-null-pwrbrand_density_pbj_slyt682-asset-mc-ElectronicDesign_density_layer2-wwe&ts=1653618771578&ref_url=https%253A%252F%252Fwww.electronicdesign.com%252F
Tomi Engdahl says:
How to Solve Analog High Voltage Delivery Challenges with a Bootstrap Approach
https://www.digikey.com/en/articles/how-to-solve-analog-high-voltage-delivery-challenges?dclid=CPTrq5DUhvgCFQ6gGQodf9ACLA
Tomi Engdahl says:
How to Use Integrated GaN Switches for High Efficiency, Cost-Effective Offline Power Supplies
https://www.digikey.com/en/articles/how-to-use-integrated-gan-switches-for-offline-power-supplies?dclid=CMuEl47UhvgCFeFGwgod7p4F2A
Tomi Engdahl says:
https://www.digikey.com/en/articles/custom-cable-for-industrial-automation?dclid=CNL25orUhvgCFalMHgIdsLsMbg
Tomi Engdahl says:
Specification and Use of Muting Functions on Light Curtains
https://www.digikey.com/en/articles/specification-and-use-of-muting-functions-on-light-curtains?dclid=CN6O_ofUhvgCFfJNHgIdCuMMBg
Tomi Engdahl says:
EEVblog #262 – World’s Simplest Soft Latching Power Switch Circuit
https://www.youtube.com/watch?v=Foc9R0dC2iI
Want to use a single cheap momentary action push button switch to toggle your circuit power on and off? Try this circuit on for size.
Tomi Engdahl says:
#256: Capacitor types, characteristics, and applications
https://www.youtube.com/watch?v=J0TjW_0xTJU
This video describes the characteristics, features and common application for the most popular different types of capacitors – including aluminum electrolytic, tantalum, ceramic (inc NP0/C0G, X7R, Y5V, Z5U), film (inc Polyester/Mylar, Polypropelene, Polycarbonate, etc.), mica and some variable caps. Characteristics such as stability with voltage and temperature, ESR & dissipation factor, dielectric absorption, self-resonant frequency, etc. are all discussed. Notes from this video can be downloaded here:
https://www.qsl.net/w2aew/youtube/capacitor_types.pdf
Tomi Engdahl says:
#257: Power Supply Decoupling & Filtering: why we use multiple caps in different locations
https://www.youtube.com/watch?v=9EaTdc2mr34
Tomi Engdahl says:
https://www.edn.com/implementing-load-line-control-for-a-multi-phase-buck-converter/
Tomi Engdahl says:
https://hackaday.com/2022/06/02/practical-transistors-jfets/
Tomi Engdahl says:
EEVblog 1476 – Keithley 515A Wheatstone Bridge TEARDOWN & TUTORIAL
https://www.youtube.com/watch?v=JDXKrXJloSw
Teardown of the Keithley 515A Megohm Wheatstone bridge, plus a tutorial on how Wheatsone bridges work and their applications.
00:00 Keithley 515A Megohm Wheatstone bridge
03:50 – The Magic smoke test
04:00 – Zero check test
04:40 – Standardise calibration step
05:30 – Range calibration
06:21 – Measuring a 200M resistor
09:41 – Confirmation with a Keithley DMM7510 7 1/2 digit multimeter
10:37 – Weatstrong Bridge Tutorial
14:55 – Gaurd traces for high impedance measurement
16:22 – Teardown
28:25 – OUCH!
Tomi Engdahl says:
Thermal Performance: Achieving Greater Power in Smaller Spaces
https://www.electronicdesign.com/resources/whitepaper/21242787/texas-instruments-thermal-performance-achieving-greater-power-in-smaller-spaces?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220606003&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Today’s designers are tasked with squeezing more and more circuitry into the footprint of their applications. The reasons are clear: smaller parts use less power, reduce running costs, extend battery life, and permit development of faster and smarter devices with greater functionality.
As a result, increasing power density and decreasing transistor dimensions have become hallmarks of contemporary ICs. Consequently, too, engineers often find themselves searching for a component that will fit in the space they have and stay cool while delivering the power needed for their system.
Shrinking systems and components leads to higher power density, which is a measure of how much power can be processed in a given space, quantifiable as the amount of power processed per unit of volume in units of watts per cubic meter (W/m3).
The ability to get the heat out of a semiconductor package directly impacts power density
It’s best quantified by its thermal resistance, which is given by the temperature difference divided by input power. This has become increasingly important as packages continue to shrink, forcing engineers to look for new ways of optimizing thermal performance in space-constrained applications.
Tomi Engdahl says:
How to Design a Good Vibration Sensor Enclosure (Part 1)
June 7, 2022
Modal analysis is employed to provide the natural frequencies and “normal modes” possible with MEMS vibration sensor enclosures. It also highlights how much impact the geometry of the enclosure has on those frequencies.
https://www.electronicdesign.com/technologies/analog/article/21243702/analog-devices-how-to-design-a-good-vibration-sensor-enclosure-part-1?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220606053&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
https://www.geeksforgeeks.org/difference-between-jfet-and-mosfet/
http://www.hawestv.com/mtv_faq/faq_fetpreamp4.htm
Tomi Engdahl says:
https://www.diyaudio.com/community/threads/mpf102.383151/
Tomi Engdahl says:
Understanding Transformers Part 1: Inrush, Saturation and Fusing
https://www.youtube.com/watch?v=x24545H5HdU
We test a transformer using a Rigol 1054z scope and a 120 volt transformer to see what current inrush we get due to saturation, and explain transformer characteristics and fusing considerations
Understanding Transformers Part 2: Developing a Simulation Model
https://www.youtube.com/watch?v=kNQRCTioyy4
We show how to develop a simulation model of an iron core transformer by bench testing and measuring, as well as by analyzing physical characteristics. We develop a linear model in LTSpice and also a nonlinear model, including saturation effects, and compare simulation results with oscilloscope bench tests.
Understanding Transformers Part 3: Improving the Transformer Model with Bench Testing
https://www.youtube.com/watch?v=cA6QKXwiZl8
We do some actual bench testing on our 120VAC transformer by applying up to 230VAC (using our Morphon variable transformer) and measuring the current flow using our Rigol DS1054Z oscilloscope and two multimeters. We then put that model into our transient simulator software (you can use LTSpice or Matlab & Simulink) to verify our model matches reality.
Transformer Inrush in 5 minutes
https://www.youtube.com/watch?v=xQ7KO_vQR0o
A brief description of transformer inrush.
What Is Inrush Current And Why Do I Care?
https://www.youtube.com/watch?v=2xIsmRkpQLA
Fluke Clamp Meters: What Is Inrush Current And Why Do I Care?
Featuring Fluke 370 Series and Fluke 381
Tomi Engdahl says:
Transformer Inrush Current: Theory & Explanation
https://www.youtube.com/watch?v=kn9QOF5d-Sw
A SIMPLE explanation of Transformer Inrush Current. Learn the theory & formula behind magnetizing transformer inrush current and how to calculate inrush current. You can read our full article on transformer inrush current at:
https://www.electrical4u.com/magnetizing-inrush-current-in-power-transformer/
Tomi Engdahl says:
Electronics tutorial – Inductor saturation
https://www.youtube.com/watch?v=Tl_LH–5Ce8
In this video I look at magnetic saturation – what it is, how it can influence the performance of a power inductor or a filtering element, and more importantly, just how much information can you actually get about this from a datasheet.
RF Man Discusses Core Saturation Of Inductors and Ferrite Materials
https://www.youtube.com/watch?v=5iOkFIJcj2s
This video discusses core saturation of inductors and different Ferrite materials, including materials 61, 43, and 28. It demonstrates the effect of core saturation on Inductor linearity with respect to the current and voltage wave forms.
Tomi Engdahl says:
Why do we need to stabilize a MOSFET Transistor?
https://www.youtube.com/watch?v=QUVUZS6pG7Y
Tomi Engdahl says:
How to Successfully Connect and Disconnect a Supply Voltage Line
June 9, 2022
This article discusses the options a circuit designer has available to turn supply lines on and off in electronic systems. While the task sounds trivial, there are many things to consider for a proper implementation.
https://www.electronicdesign.com/power-management/whitepaper/21243974/analog-devices-how-to-successfully-connect-and-disconnect-a-supply-voltage-line?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220606059&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
N-channel or P-channel MOSFET to build an electronic switch?
Single housing or two-chip solution for the power switch and driver?
Selecting the right MOSFET driver.
Tomi Engdahl says:
The Most Versatile Voltage Converter you never heard of! The (S)EPIC Converter
https://www.youtube.com/watch?v=XOcA7ijtlCY
In this video we will be having a closer look at the SEPIC voltage converter. You probably do not know it, but most small Buck Boost Converters are in fact SEPIC converters and for a good reason. I will show you how the SEPIC converter works, why it is “(S)EPIC”, how you can modify it with a coupled inductor and how to make a DIY version. Let’s get started!
0:00 SEPIC Converter?
1:54 Intro
2:29 How does it work?
5:20 Advantages of the SEPIC
6:05 Secret Coupled Inductor Hack?
9:21 Which SEPIC should you buy?
9:49 DIY SEPIC
Tomi Engdahl says:
Here is why MOSFET drivers are sometimes essential! || MOSFET Driver Part 1 (Driver, Bootstrapping)
https://www.youtube.com/watch?v=8swJ_Bnsgl4
In this video we will be having a closer look on how to drive MOSFETs. That means I will show you different examples on how to turn on/off a MOSFET with a microcontroller. We will investigate why and how much gate current is flowing and how the gate capacitance pretty much forces us to use a MOSFET driver at some point. Along the way you will also learn about what bootstrapping is and when to use it and you will hear a tiny bit about a gate-drive transformer. Let’s get started!
Electronic Basics #28: IGBT and when to use them
https://www.youtube.com/watch?v=RxRJW09A_XA
In this episode of Electronic Basics I will tell you how you can use an IGBT instead of a MOSFET to switch your load on and off and when it actually makes sense to use them instead of MOSFETs.
Tomi Engdahl says:
Reduce Noise by Synchronizing Switching Regulators
June 20, 2022
Switching regulators are often incorporated into today’s circuit designs to boost power-conversion efficiency. However, emissions come into play, and that requires synchronization with the help of a clock-signal generator.
https://www.electronicdesign.com/power-management/whitepaper/21244667/analog-devices-reduce-noise-by-synchronizing-switching-regulators?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220617016&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
https://www.edn.com/current-sensing-considerations-in-a-bridgeless-totem-pole-pfc/
Tomi Engdahl says:
How to Use eFuses to Design Compact Short Circuit, Overvoltage, and Thermal Protection Solutions
https://www.digikey.com/en/articles/how-to-use-efuses-to-design-compact-short-circuit-overvoltage-and-thermal-protection-solutions
Tomi Engdahl says:
Sensorless, Anti-Reverse Rotation Startup for Blower Fan Motors
June 21, 2022
This article describes how initial rotor position detection techniques can overcome the challenge of providing anti-reverse, fast, sensorless startup in motor designs.
https://www.electronicdesign.com/industrial-automation/article/21244782/allegro-microsystems-sensorless-antireverse-rotation-startup-for-blower-fan-motors?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220620077&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
Startup techniques employed to overcome the problem of determining magnet position in BLDC designs.
Cost-saving and power-efficiency incentives using sensorless motor drivers.
Motor-driver solutions that leverage a field-oriented-control (FOC) system.
Tomi Engdahl says:
https://www.electronicdesign.com/industrial-automation/article/21244970/electronic-design-conformalcopper-coating-transforms-component-into-its-own-heat-spreader?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220620018&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Class AB Op Amps: The Solution for Low-Iq Audio
June 22, 2022
Want a high-performance audio amplifier with great quiescent-current performance numbers? The class AB amplifier improves the efficiency and lowers the distortion versus other amps.
https://www.electronicdesign.com/technologies/analog/article/21244938/electronic-design-class-ab-op-amps-the-solution-for-lowiq-audio?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220620018&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
Different classes of amplifiers.
What are the benefits of class AB amplifiers?
Patents that address the quiescent current of class AB amps.
Amplifiers have many classifications, and each class has its advantages and disadvantages. The different classes of amplifiers are A, B, AB, C, D, E, F, T, and even more “alphabet soup.” Designers typically work with classes A, B, AB, and C.
The class A amplifier has high linearity with high gain ability. It has a 360-degree conduction angle that leads to the amplifier remaining in the active state at all times, and it’s able to use the entire input signal. The class A amp has good high frequency and feedback-loop stability.A drawback is that it only has 25% to 30% efficiency.
Class B amplifiers use two active devices that are biased one-by-one, each in half of the actual full cycle, meaning that every device will only be biased during 180 degrees of the cycle. Two transistors provide the combined current drive to the load. This improves the efficiency as compared to the 25% to 30% efficiency of the class A amp.
Class C amplifiers operate in two different operating modes, tuned or untuned (class C amps have a huge distortion across their output). The efficiency of this amplifier is much higher than the A, B, or AB: A maximum 80% efficiency can be achieved, especially in radio-frequency-related applications.
What is a Class AB Amplifier?
Class AB amplifiers overcome the cross-over distortion that plagues class B amplifiers. The class AB amplifier, which combines class A and class B amps, eliminates the low-efficiency issues of class A amplifiers, and reduces the distortion and improves on the poorer linearity exhibited by class B amps.
The class AB configuration has a reduced efficiency and dissipates a reasonable amount of power while in the zero-input condition. Class B has the highest efficiency at 78.5%, followed by class AB, which is between 78.5% to 50%, and then class A at 50%. In terms of distortion, class A has the lowest, followed by class AB, with class B bringing up the rear.
Audiophiles, or “Golden Ears” as we called them in my audio days at Empire Scientific Corporation during the 1970s, typically like class AB amplifiers because of their “warmth” or “coloration,” which was really relished at the digital amplifier outputs.
Many “Golden Ears” claim that digital amplifiers are less likely to “color” the sound. Analog amplifiers are particularly useful for the mid- and high-ranges due to this “coloration.” That’s why they’re preferred in the amplifier substages, since the signal starts out more like the original recordings.
A disadvantage of the class AB amplifier is that temperature matching of each current mirror will be necessary, especially when emitter degeneration resistors aren’t used, such as in Figure 2.
Tomi Engdahl says:
A Guide to Coupled Inductors
https://www.coilcraft.com/en-us/edu/series/a-guide-to-coupled-inductors/?utm_source=Newsletter&utm_medium=Email&utm_campaign=PersonifAI_Newsletter
Tomi Engdahl says:
Understanding and Selecting Isolation Transformers
https://www.coilcraft.com/en-us/edu/series/understanding-and-selecting-isolation-transformers/
Tomi Engdahl says:
Document 1009-C Revised 01/25/21Considerations for selecting a common mode choke
Common Mode Filter
Chokes for High Speed
Data Interfaces
https://www.coilcraft.com/getmedia/7e792dc7-ba82-47a6-923c-a02a52ee4446/doc1009_cm_chokes_hi_speed.pdf?utm_source=Newsletter&utm_medium=Email&utm_campaign=PersonifAI_Newsletter
Tomi Engdahl says:
A Guide to Flyback Transformers
https://www.coilcraft.com/en-us/edu/series/a-guide-to-flyback-transformers/?utm_source=Newsletter&utm_medium=Email&utm_campaign=PersonifAI_Newsletter
Tomi Engdahl says:
Magnetics for Power over Ethernet (PoE)
https://www.coilcraft.com/en-us/edu/series/magnetics-for-power-over-ethernet/
What is Power over Ethernet?
Power over Ethernet, or PoE, is a method of delivering power to remote powered devices (PDs) using twisted–pair Ethernet cables of up to 100 meters in length. General applications include IoT, Building Automation, and Industrial Lighting. Powered devices include IP security cameras, wireless and Bluetooth access points, network routers and repeaters, VoIP phones, PDA charging systems, and LED lighting and controllers. PoE eliminates the time, expense, and required space of installing a separate line voltage power outlet, and allows for power management and control of many devices from a central location.
PoE operates in the lower voltage telecom range – generally in the 36 – 57 V range, but up to 73 V – typically over category 5 (cat 5) Ethernet cables. This gives PoE a safety advantage over standard line voltage (110/220 V) power outlets.
What is the PoE Standard?
Requirements for PoE have been defined by the IEEE 802.3 working group as part of the 802.3 Ethernet standard. The sections particular to PoE define the physical requirements and protocols for specific data rates and various power levels over Ethernet cables. Data rates for Ethernet have evolved from the 10/100 megabits per second (Mbps) frame rates of 10/100BASE–T to the gigabits per second (Gbps) rate of 1000BASE–T Gigabit Ethernet (GigE).
New IEE 802.3 versions for PoE have been published over time address market demands for higher power levels to be delivered to powered devices. The following shows the power delivered to the powered device (PD) for each revision:
IEEE 802.3af–2003 up to 12.95 W
IEEE 802.3at–2009 up to 25.5 W (2–pairs, medium power)
IEEE 802.3at–2009 up to 51 W (4–pairs, high power)
IEEE 802.3bt–draft 2.0 up to 71 W (a.k.a 4PPoE)
PoE equipment includes power sourcing, midspan, and powered devices:
How Much Power is Available?
The maximum power delivered by the PSE has also evolved from a maximum of 15.40 W for IEEE 802.3af PoE up to 100 W for IEEE 802.3bt. The upcoming IEEE 802.3bt standard includes eight Classes, which describe PD power supply limits ranging from 3.84 W for Class 1 to 71.3 W for Class 8. Non-standard PoE devices may provide up to 90 W power to the powered device.
How is power provided over Ethernet cables?
There are three ways to deliver power with PoE:
Through the data pair
Through the spare pair
Through a mid span device (For legacy equipment)
How are magnetic components used in PoE?
In the signal path, center-tapped 1:1 transformers are used for injecting current, and common mode chokes are used to filter out EMI.
Signal path isolation transformers for both the transmit and receive sections are incorporated into a single package in Coilcraft HPX2126L
Common mode chokes for both transmit and receive sections are also incorporated into a single package in Coilcraft HPF2187L
Tomi Engdahl says:
The Difference Between Class 2 and Class II Power Supplies
https://slpower.com/archives/11643