Innovation is critical in today’s engineering world and it demands technical knowledge and the highest level of creativity. Seeing compact articles that solve design problems or display innovative ways to accomplish design tasks can help to fuel your electronics creativity.
You can find many very circuit ideas at ePanorama.net circuits page.
In addition to this links to interesting electronics design related articles worth to check out can be posted to the comments section.
1,841 Comments
Tomi Engdahl says:
Simulation Model
Considerations: Part I
https://www.coilcraft.com/getmedia/cc3b26f1-9d9c-4bf5-9c0f-0590b8830dfd/Doc1710_Inductor-Model-App_Note_Part1.pdf?utm_source=Newsletter&utm_medium=Email&utm_campaign=PersonifAI_Newsletter
Tomi Engdahl says:
What is the Essence of Quiescent Current?
Feb. 16, 2022
The definition of quiescent is “a state or period of inactivity or dormancy.” In electronics, quiescent current is the current flowing into a system in standby mode with a light or no load.
https://www.electronicdesign.com/power-management/whitepaper/21215797/electronic-design-what-is-the-essence-of-quiescent-current?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221222027&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Document 1500 Revised 10/1/18Technical Bulletin
Forward or Flyback? Which is Better? Both
https://www.coilcraft.com/getmedia/e9e583a1-3eb8-4ffe-9304-51fab8eb795b/Doc1500_Forward-vs-Flyback.pdf?utm_source=newsletter&utm_medium=email&utm_campaign=PersonifAI_Forward_Flyback
In this article, we will focus on forward or flyback. We’ll
discuss the characteristics of active clamp forward and con-
tinuous conduction flyback isolated power supply topologies
and demonstrate the design and performance trade-offs
of each using two telecom-oriented power supplies as ex-
amples. Specifically, we show 51 W Power over Ethernet
(PoE) Powered Devices (PD) supplies that are appropriate
for use in the IEEE 802.3bt standard
So, Which is Better?
The discussions in this article should make it clear that
forward and flyback power supplies have unique charac-
teristics that make each suitable for optimizing different
requirements: cost, size, and efficiency. Boiling down all
the above attributes, one could argue that flybacks should
still be considered the default choice for most power supply
requirements due to their somewhat smaller size, lower cost,
and comparably high efficiency. When the supply require-
ment exists for the absolute best in efficiency, the forward
topology should be considered first. So, which is better?
Both!
Tomi Engdahl says:
Fundamentals of EMI
Requirements for an
Isolated DC/DC Converter
https://www.ti.com/lit/wp/slyy202/slyy202.pdf?HQS=null-null-pwr-pwr_gen_slyy202-asset-whip-ElectronicDesign_psfi_lowemi_l2-wwe_awr&ts=1672295155476&ref_url=https%253A%252F%252Fwww.electronicdesign.com%252F
Tomi Engdahl says:
Achieving GaN Products With Lifetime Reliability
https://www.ti.com/lit/wp/snoaa68/snoaa68.pdf?HQS=null-null-hv-hvpwrconversion_snoaa68-asset-whip-electronicdesign_psfi_gan_l1-wwe_awr&ts=1672295172021&ref_url=https%253A%252F%252Fwww.electronicdesign.com%252F
TI achieved reliable GaN products through a comprehensive in-house program ranging from epitaxial growth,
application reliability validation, and the industry support of new GaN standards.
Gallium-nitride (GaN) high-electron mobility transistors (HEMTs) or field-effect transistors (FETs) are enabling an
exciting and disruptive era in power conversion. The material properties of GaN have enabled power switches
with much lower on-resistance and higher switching speeds than equivalently-sized silicon power transistors.
These benefits are making power conversion solutions more compact and energy efficient. GaN FETs have
benefited both from established reliability methodologies for silicon FETs, as well as new methodologies to
validate GaN FET reliability under application conditions. This white paper describes the progress and shows
that TI GaN products now have proven reliability in application
Tomi Engdahl says:
Increasing power density with an integrated GaN solution
https://e2e.ti.com/blogs_/b/powerhouse/posts/increasing-power-density-with-an-integrated-gan-solution-1561459668?HQS=null-null-hv-hvpwrconversion_gan_solution-asset-ta-electronicdesign_psfi_gan_l2-wwe_awr
Tomi Engdahl says:
What’s the Difference Between Silicon Carbide and Silicon?
March 23, 2022
Silicon carbide has already contributed significantly toward electromobility and digitization of industrial processes. But what is SiC, how does it differ from traditional silicon, and what makes it an ideal material to accelerate EV goals?
https://www.electronicdesign.com/power-management/whitepaper/21236972/onsemi-whats-the-difference-between-silicon-carbide-and-silicon?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221222029&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Essentials for Effective Protection Against Overvoltage Events
July 20, 2022
While there’s no one-size-fits-all circuit protection solution, robust overvoltage protection is a necessity in virtually any application that connects to a power line. This article explores how to pinpoint the right solution based on app requirements.
https://www.electronicdesign.com/power-management/whitepaper/21246147/bourns-inc-essentials-for-effective-protection-against-overvoltage-events?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221222029&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
Determining the optimal overvoltage circuit protection strategy based on the “Three Ds” of device functionality.
A better understanding of voltage-switching vs. voltage-clamping technologies.
Why device core materials and technologies matter in selecting an overvoltage protection solution.
Potentially damaging electrical overvoltage threats are an everyday occurrence in today’s electrical and electronic world. Their intensity ranges from very light electrostatic-discharge (ESD) events to very intense lightning strike-induced surges on data lines and power lines. These events have the potential to lock up microprocessors, damage sensors, cripple computer communications ports, cause severe damage to equipment, and even threaten harm to users through electrical shock or cause a fire.
To address this wide range of threats, an equally wide range of circuit protection technologies is available. Currently available components span from small, fast PCB-mounted components to large, rugged wall-mounted devices. Some of these devices are binary in nature—they switch on or off. Others are more proportional or linear in their response to events.
The response to an overvoltage event can be classified into one of the “3Ds”:
1. Divert excess energy to ground: Often referred to as “voltage switches,” these devices switch their impedance to a very low level once their terminal voltage reaches a threshold value chosen by the designer, sending the excess current to ground.
2. Dissipate excess energy: Regularly known as “voltage clamps,” these devices lower their impedance across the protected line to attempt to limit or regulate the voltage to a level chosen by the designer.
3. Disconnect the load from the line: This unique technology attempts to open like a fuse and limit or block current flow when the line voltage exceeds a value chosen by the designer.
Tomi Engdahl says:
Demystifying Input Supply
Current in DC/DC Regulators:
From Shutdown to Full Load
https://www.ti.com/lit/wp/slyy189/slyy189.pdf?HQS=null-null-pwr-pwr_gen_slyy189-asset-whip-ElectronicDesign_psfi_lowiq_l2-wwe_awr&ts=1672327054529&ref_url=https%253A%252F%252Fwww.electronicdesign.com%252F
Tomi Engdahl says:
3 quiescent-current (Iq) specifications to understand
https://e2e.ti.com/blogs_/b/powerhouse/posts/3-quiescent-current-iq-specifications-you-need-to-understand?HQS=null-null-pwr-pwr_gen_3_specifications-asset-ta-ElectronicDesign_psfi_lowiq_l1-wwe_awr&DCM=yes&dclid=COm1s5L-oPwCFULKOwId2-gKjA
A common definition of quiescent current (IQ) is the current drawn by an integrated circuit (IC) in a no-load and nonswitching but enabled condition. A broader and more useful way to think about it is that quiescent current is the input current consumed by an IC in any number of its ultra-low-power states.
For battery-powered applications, this input current comes from the battery, so it determines how long the battery operates before it either needs recharging (for rechargeable batteries, such as lithium-ion (Li-Ion) or nickel metal hydride (Ni-MH)) or replacing (for primary batteries, such as alkaline or lithium manganese dioxide (Li-MnO2)). For battery-powered applications that spend a large amount of their time in standby or sleep mode, IQ can impact the battery’s run time by years. For example, using an ultra-low-IQ buck converter like the 60-nA TPS62840 to power an always-on application, such as the smart meters shown in figure 1, enables 10 years of battery run time.
Tomi Engdahl says:
Isolation
Increase safety with higher reliability isolation at a lower system cost
https://www.ti.com/technologies/isolation.html?HQS=null-null-hv-hvisolation_isolation-asset-pp-electronicdesign_psfi_isolation_l1-wwe_awr&DCM=yes&dclid=CJvk0oX-oPwCFcfJOwId5ikNPQ
Galvanic isolation is a method of electrically separating two domains, allowing power or signals to transfer across the barrier without compromising human safety, while also preventing ground potential differences and improving noise immunity. Our portfolio of proprietary isolation techniques, including a robust capacitive SiO2 insulation barrier and integrated IC transformer-based magnetic isolation, helps exceed Verband der Automobilindustrie (VDA), Canadian Standards Association (CSA) and Underwriters Laboratory (UL) standards without compromising performance.
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=null-null-hv-hvisolation_analogwire-asset-ta-electronicdesign_psfi_isolation_l2-wwe_awr&DCM=yes&dclid=CPTT4oX-oPwCFcLLOwIdLtYJnw
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).
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Tomi Engdahl says:
Understanding SOA Curves to Operate at High Output
Currents and Temperature
https://www.ti.com/lit/an/sluaaj1/sluaaj1.pdf?HQS=null-null-pwr-pwr_gen_sluaaj1-asset-mc-ElectronicDesign_psfi_density_l3-wwe_awr&ts=1672642366898&ref_url=https%253A%252F%252Fwww.electronicdesign.com%252F
Tomi Engdahl says:
The Golden Rule of Board Layout for SMPS
Aug. 4, 2022
One factor tops all others in optimizing board layout for switched-mode power supplies, and it has to do with designing traces, especially in terms of their length.
https://www.electronicdesign.com/power-management/whitepaper/21248133/analog-devices-the-golden-rule-of-board-layout-for-smps?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221222030&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
Achieving an optimized board layout by successfully implementing the golden rule regarding traces.
Looking at typical buck and boost regulator circuits.
This article explains the basis for achieving an optimized board layout, a critical aspect in the design of switch-mode power supplies (SMPS). A good layout ensures stable functioning of the switching regulator and minimizes radiated interference as well as conducted interference (EMI)—widely known by electronics developers. However, what’s not generally known is how an optimized board layout for a switch-mode power supply should look.
Tomi Engdahl says:
https://www.electronicdesign.com/technologies/analog/article/21253369/electronic-design-whats-all-this-floobydust-stuff-anyhow
Tomi Engdahl says:
https://www.electronicdesign.com/power-management/whitepaper/21254547/electronic-design-advanced-battery-technologies-will-help-transform-our-energy-economy?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221103030&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
What’s the Difference: Serial Communications 101
June 1, 2021
Communication is the hallmark of IoT and computer systems in general. Here are some of the basics.
https://www.electronicdesign.com/technologies/communications/whitepaper/21127800/whats-the-difference-serial-communications-101?utm_source=EG+ED+Connected+Solutions&utm_medium=email&utm_campaign=CPS221229044&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
https://www.edn.com/a-safe-adjustable-regulator/
Tomi Engdahl says:
https://www.allaboutcircuits.com/technical-articles/an-introduction-to-current-source/
Tomi Engdahl says:
Reliable Power Switch for Privacy Apps Has Offline Memory
Jan. 5, 2023
The circuit described in this article, essentially a replacement for a mechanical toggle switch, isn’t connected to the gadget’s processor, making it impossible to hack in and turn on/off the camera and/or microphone remotely.
https://www.electronicdesign.com/technologies/analog/article/21257455/renesas-electronics-reliable-power-switch-for-privacy-apps-has-offline-memory?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS221229028&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn:
How to implement a more secure power switch, replacing a mechanical toggle switch, for multiple applications.
Components involved in setting up the power switch.
Specifics of macrocell operation.
The circuit described in this article is designed for devices that need to prioritize privacy. For example, in gadgets with a camera and/or microphone, the user has to be sure that the camera (microphone) is turned off if desired, even after the gadget was powered off and on again for a long period. Also, if someone with bad intentions wants to hide the fact that the camera (microphone) is on by removing the LED indicator (or shortening it), the camera (mic) will be turned off automatically.
The circuit isn’t connected to the gadget’s processor, making it impossible to hack in and turn on/off the camera and/or microphone remotely.
Tomi Engdahl says:
Bench Variac
Putting my vintage Powerstat Type 21 variable transformer to good use.
https://hackaday.io/project/188999-bench-variac
Tomi Engdahl says:
The End of the Full Bridge Rectifier? (Sorry ElectroBOOM) Active Rectifier is here!
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:
8 awesome application of diodes in circuits
https://www.youtube.com/watch?v=uEIRXYQO4_Y
Tomi Engdahl says:
How To Test A Crystal Oscillator Using An AWG and a ‘Scope
https://www.youtube.com/watch?v=BiVnPr9-qIk
In this video we look at one method of test if a crystal oscillator is working or not. We place the DUT in series between the AWG and the oscilloscope. When we reach the resonant frequency of the Xtal, the voltage (amplitude) on the ‘scope will jump. This will only happen at the resonant frequency.
Tomi Engdahl says:
Build A Cheap DIY Signal Injector Pen Useful For Electronics Fault Finding – In A Pen!
https://www.youtube.com/watch?v=_aI6TLLVpDQ
Tomi Engdahl says:
https://www.edn.com/the-electronic-analogue-of-the-push-button-switcher/
Tomi Engdahl says:
https://www.edn.com/partners-unveil-gan-audio-amp-reference-design/
Tomi Engdahl says:
https://www.homemade-circuits.com/how-to-make-simple-boost-converter-circuits/
Tomi Engdahl says:
https://www.edn.com/the-diverging-worlds-of-sic-and-gan-semiconductors/
Tomi Engdahl says:
https://www.digikey.com/en/articles/connector-gland-and-grip-options-for-industrial-automation-cabling?dclid=CJixld6czvwCFWOQ_Qcd2qcMyA
Tomi Engdahl says:
https://www.digikey.com/en/articles/use-high-current-igbt-drivers-with-built-in-protection?dclid=CJLAyOWczvwCFWFV5QodPOALDw
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=COSdoeWczvwCFUDGuwgdNwkFvQ
Tomi Engdahl says:
https://www.edn.com/my-favorite-design-idea-of-all-time/
Tomi Engdahl says:
https://www.edn.com/power-tips-113-two-simple-isolated-power-options-for-8-w-or-less/
Tomi Engdahl says:
Document 1500 Revised 10/1/18Technical Bulletin
Forward or Flyback? Which is Better?
https://www.coilcraft.com/getmedia/e9e583a1-3eb8-4ffe-9304-51fab8eb795b/Doc1500_Forward-vs-Flyback.pdf?utm_source=newsletter&utm_medium=email&utm_campaign=PersonifAI_Forward_Flyback
Tomi Engdahl says:
Document 1732 Revised 03/30/221
Technical Bulletin
TX1 Series Push-Pull Isolation Transformers
Optimized for use with Texas Instruments SN6507 High Frequency Drivers
https://www.coilcraft.com/getmedia/522af81d-ddef-4e7f-b314-0ea02bf65b97/Doc1732_Push-Pull_TechBull_TX1.pdf?utm_source=newsletter&utm_medium=email&utm_campaign=PersonifAI_Tech_Bulletin_Push_Pull_Transformers_TISN6507
Document 1140-C Revised 01/11/21Exploring the Need for Smarter Power Inductor Specification Tools
Looking Beyond the
Static Data Sheet
https://www.coilcraft.com/getmedia/9998b1e0-c4f5-47e1-bce4-053869e250d9/Doc1140_Beyond_the_data_sheet_Part1.pdf?utm_source=newsletter&utm_medium=email&utm_campaign=PersonifAI_Beyond_Datasheet_Smarter_Power_Tools
Tomi Engdahl says:
How to Mitigate EMI in Electric and ICE Vehicles
Jan. 20, 2023
EMI can be a disturbance to both gas-powered- and electric-vehicle operation. EMC testing will help verify standards compliance.
https://www.electronicdesign.com/power-management/whitepaper/21258511/electronic-design-how-to-mitigate-emi-in-electric-and-ice-vehicles?utm_source=EG+ED+Auto+Electronics&utm_medium=email&utm_campaign=CPS230119092&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
The Evolution of Modern Calibration
Jan. 24, 2023
The science of measurement has evolved from the cubit to the latest calibration tools. What’s on the horizon?
https://www.mwrf.com/technologies/test-measurement/article/21258677/fluke-the-evolution-of-modern-calibration?utm_source=RF+MWRF+Today&utm_medium=email&utm_campaign=CPS230127051&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
What you’ll learn
Why is calibration important?
How calibration techniques have changed over time.
Tomi Engdahl says:
https://www.electronicsforu.com/electronics-projects/simple-battery-charger-with-overcharge-protection
Tomi Engdahl says:
https://www.edn.com/simulation-tool-checks-pcb-signal-integrity/
Tomi Engdahl says:
https://www.edn.com/universal-purpose-optoelectronic-logic-elements/
Tomi Engdahl says:
A look at conical inductors
https://www.edn.com/a-look-at-conical-inductors/
One approach to making the RF choke is to wind an inductor as a conical spiral as follows.
With the conical arrangement of turns, the highest frequencies in the signal spectra are supported by the inductance near the conical tip while the lower frequencies are supported by the larger turns further away from the signal line itself. Both the Cm and Cn capacitances are kept small close to the signal line and allowed to be larger away from the signal line where their effects are less critical.
Tomi Engdahl says:
Phase-Noise Modeling, Simulation, and Propagation in Phase-Locked Loops (Part 1)
Feb. 3, 2023
This three-part series discusses how phase noise in general is modeled and simulated, and how RF component phase noise propagates through a PLL to determine its output phase noise.
https://www.electronicdesign.com/technologies/analog/article/21259312/phasenoise-modeling-simulation-and-propagation-in-phaselocked-loops-part-1?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS230119074&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
The Secret to Quiet, Efficient BLDCs: The Motor Driver
Oct. 18, 2021
Sponsored by Texas Instruments: A sensorless, code-free driver delivers a quick and successful solution to a difficult BLDC motor design application.
https://www.electronicdesign.com/power-management/whitepaper/21177125/texas-instruments-the-secret-to-quiet-efficient-bldcs-the-motor-driver?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS230119074&o_eid=7211D2691390C9R&rdx.identpull=omeda|7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
Navigating the Challenges of Designing for a Multi-Platform Embedded Computing Solution
https://www.xes-inc.com/news-media/product-briefs-whitepapers/navigating-the-challenges-of-designing-for-a-multi-platform-embedded-computing-solution/
Tomi Engdahl says:
Kun tehonsyötön on pakko toimia
https://etn.fi/index.php/tekniset-artikkelit/14570-kun-tehonsyoetoen-on-pakko-toimia
Tomi Engdahl says:
https://www.edn.com/how-gate-driver-enables-a-wide-range-of-battery-voltages/
Tomi Engdahl says:
https://www.allaboutcircuits.com/technical-articles/introduction-to-double-date-rate-ddr-memory/
Tomi Engdahl says:
How a fully-stackable eFuse can help meet ever-increasing power needs of servers
https://e2e.ti.com/blogs_/b/powerhouse/posts/meet-ever-increasing-power-needs-in-server-designs-with-a-scalable-efuse-solution?HQS=app-lp-pwr-density_thermals_efuses-agg-ta-ElectronicDesign_pwr-wwe&DCM=yes&dclid=COGLy9mbl_0CFW-g_QcdiPAIqA
As demand for data increases, so does demand for servers and data centers, and thus higher demand for power. Industry trends suggest that power per rack, which was 4 kW in 2020, will be as high as 20 kW in 2025.
Given limited physical real estate available for data centers and servers, the delivery of more power in less area is known as a high power density requirement in server power architectures. Increasing the efficiency of server power supplies can also keep cooling costs down.
Servers are usually scalable and are hot-swappable in order to meet different processing requirements and maintain high system availability. To achieve seamless hot-swap functionality, server motherboards and power distribution boards employ hot-swap controllers or eFuses. Components such as eFuses in server power supplies need to provide higher current to meet increased server power requirements. Protection devices such as hot swaps and eFuses also need to handle high peak current to match the higher peak-processing capabilities of modern microprocessors in servers.
Traditionally, high-power server designs include hot-swap controllers with multiple metal-oxide semiconductor field-effect transistors (MOSFETs). But server power and power-density requirements are increasing exponentially. To satisfy these needs and simplify these designs, consider the TPS25985 (80 A peak) and TPS25990 (60 A peak with the PMBus interface) eFuses in server power architectures. The TPS25985 and TPS25990 can support 60 ADC and 50 ADC, respectively, and have an adjustable current limit of up to 60 A and 50 A, also respectively. It is possible to stack multiple unlimited TPS25985 and TPS25990 eFuses to achieve higher current.
Achieving high power density
Power density is a must-have requirement for modern server power supply units (PSUs). The latest generation of server PSUs are in the range of a 3-kW (250 A at 12 V) power rating. When selecting an eFuse, it is important to have the highest current in the smallest size. The TPS25985 packs 80 A of peak current in a 4.5-mm-by-5-mm package. Figure 3 shows some of the TI’s eFuses.
By integrating a MOSFET, a current monitor, a comparator, active current sharing and a temperature monitor, the TPS25985 and TPS25990 eFuses significantly reduce the total printed circuit board or printed wiring board area.
Current-share and current-monitor accuracy
Hot-swap controllers cannot control the gates of multiple paralleled MOSFETs very precisely; therefore, current sharing by paralleled MOSFETs is not accurate. Precision amplifiers can help achieve high current-share accuracy and current-monitor accuracy, but adding them increases the total solution size. It is challenging to gauge the die temperature of the MOSFET, and therefore impossible to guarantee its thermal protection in transient and steady-state conditions.
The TPS25985 and TPS25990 eFuses have integrated active current sharing and direct access to MOSFET die parameters (voltage, current, temperature), which allows accurate control of all eFuse gates connected in parallel and accurate die temperature monitoring of integrated FETs. Compared to an eFuse without active current sharing, the TPS25985 and TPS25990 enable design engineers to optimize the number of eFuses and the performance of the system.
Remote monitoring and control
The TPS25990 adds PMBus interface capability to the system. The TPS25990 enables single-command power cycling with an adjustable turnon delay, which allows system design engineers to sequence and reset the system remotely. The TPS25990 also offers black-box capability, where seven events are recorded with relative timestamps. The TPS25990 incorporates high-speed analog-to-digital converters that enable users to plot one signal of their choice, mimicking a digital oscilloscope. The GUI for the TPS25990, along with its other features, helps design engineers not only reduce their total development time but also quickly identify and resolve field issues, which are generally very difficult to reproduce and troubleshoot.
Thermal considerations
Server power systems operate at a wide ambient temperate range (–40ºC to 85ºC). Hot-swap controllers or eFuses experience even higher ambient temperatures. Therefore, power design engineers become concerned about the thermal performance of these devices when high currents are packed in small packages. The TPS25985 and TPS25990 eFuses alleviate this concern, with the ability to operate at a 125ºC junction temperature. The TPS25985 and TPS25990 offer an RDS(on) of 0.59 mΩ and 0.79 mΩ, respectively; RDS(on) spread across process, voltage and temperature variations is limited. Thus, these eFuses experience very low self-heating and a wide operating temperature range without sacrificing the derating. Figure 6 shows the case temperature of the TPS25985.
Conclusion
Design engineers can reduce development time and design cost by using the TPS25985 and TPS25990 eFuses in server power architectures. The eFuses’ low RDS(on) reduces power losses in the system, helping data centers achieve their efficiency goals.