What this page solves

eFuse and Hot-Swap controllers in power supplies protect 65–300 W adapters, server PSUs and bench supplies from inrush stress, MOSFET overstress and unpredictable fuse behaviour during plug-in and fault conditions. They turn a fragile, one-shot protection scheme into a configurable, observable and remotely recoverable protection layer.

When an adapter is plugged into the mains, when a server PSU module is hot-plugged into a powered backplane, or when a bench PSU channel is connected to a new circuit, large output capacitors and unknown loads can pull high inrush current. With only fuses, NTCs and Schottky OR-ing, the result is often blown MOSFETs, nuisance fuse trips or even a full system shutdown.

Traditional fuses and NTCs are slow, temperature-dependent and non-configurable. They cannot distinguish between a one-off wiring mistake and a slowly degrading load, and they offer no telemetry to help maintenance teams understand why an outage happened. Schottky OR-ing adds conduction loss and heat without delivering real fault visibility or time-selective protection.

In contrast, eFuse and Hot-Swap controllers add programmable current limits, controlled dv/dt soft-start, SOA-aware fault timers and reverse current blocking. With integrated telemetry, they report bus voltage, load current and fault causes to a digital PSU controller or system MCU so that field data can distinguish “rare user short” from “load aging” and support remote recovery instead of on-site fuse replacement.

This page focuses on DC-side eFuse and Hot-Swap functions around adapter and PSU outputs. High-speed OV/OC/SCP comparators are covered in the dedicated “OV/OC/SCP Protection” page, hold-up and backup supercapacitor or battery schemes are covered in “Hold-Up / Backup for Adapters”, and rack-level or distribution-level solid-state fuses are discussed in the general “eFuse (Solid-State Fuse)” topic.

eFuse & Hot-Swap in adapter/PSU architectures

In a modern adapter or PSU, eFuse and Hot-Swap controllers sit in the DC domain around the main output bus and module interfaces, not in the AC input and EMI front-end. Their role is to shape inrush, protect MOSFETs and confine faults at the 12 V, 24 V or 48 V bus and at each output rail, while the AC input section focuses on safety, surge immunity and conducted and radiated emissions.

A typical architecture starts with AC input filtering and surge protection, followed by a bridge rectifier and a PFC stage where required. A primary DC-DC stage such as a flyback, LLC or active bridge then generates the main DC bus. eFuse and Hot-Swap devices are inserted after this conversion stage, either directly on the main bus or in front of each output connector or rail to localise faults and provide controlled hot-plug and hot-unplug behaviour.

Input Hot-Swap controllers manage the inrush current when a module or board is plugged into a live DC backplane, for example when a server PSU module is inserted into a running chassis. They pre-charge the module capacitors, respect MOSFET SOA and prevent the backplane voltage from collapsing. Output eFuses sit downstream and protect loads on the 12 V, 24 V or laboratory outputs against shorts and overloads, while also providing reverse blocking and optional ideal-diode OR-ing between supplies.

For low to medium current rails, multi-channel load switches or eFuse ICs can protect several outputs in one device. For higher current server and industrial supplies, single-channel Hot-Swap controllers with external MOSFETs supervise tens of amperes on the main bus. Across these placements, all devices operate on the DC side; AC safety clearances, surge arrestors and EMI filters remain the responsibility of the AC Input & EMI Front-End stage.

Soft-start current limiting & inrush control

Soft-start current limiting allows an eFuse or Hot-Swap controller to charge large output capacitors in a controlled way, shaping the inrush current profile and avoiding overstress on MOSFETs and upstream supplies. By coordinating the current limit, dv/dt and soft-start time window, adapters and PSUs can tolerate large capacitive loads without trigger-happy protection or excessive voltage sag on the main bus.

During soft-start, the device either enforces a programmed current limit or enforces a controlled voltage ramp across the load. With near constant-current behaviour, the time to charge the output capacitor can be estimated from the effective capacitance, the target output voltage and the chosen current limit. With dv/dt control, the slew rate is tuned to keep both EMI and MOSFET dissipation within acceptable bounds, while still reaching regulation fast enough for the end application.

The same current limit used for soft-start must also distinguish between a benign inrush and a genuine fault. eFuse controllers therefore combine current limiting with fault timing: a soft-start or inrush window allows capacitive loads to settle, while a programmable fault timer terminates sustained overloads that outlive this window. Fast, microsecond-scale protection handles severe shorts, while millisecond-scale timers control how long a device may remain in a high dissipation region before shutting down or retrying.

Current limits can be set with a resistor or digitally over an I²C or PMBus interface. Resistor programming is attractive for fixed-power adapters, where one limit maps cleanly to one power rating. Digital programming is more useful in server and bench supplies, where firmware can adapt current limits and dv/dt to different operating modes or test conditions and log the chosen values alongside fault events.

Foldback limiting and constant-current limiting offer different trade-offs. Constant-current limiting keeps the inrush current near a fixed level, which simplifies timing estimates but can load the MOSFET heavily during long events. Foldback reduces current as the voltage across the device increases, easing thermal stress at the cost of deeper voltage droop on the protected rail. For compact 65 W adapters with low-ESR output capacitors, a moderate constant-current limit and a controlled dv/dt often give sufficient margin, while server PSU modules with very large bus capacitance favour tighter control of both current and timing.

NTC thermistors and X-cap discharge networks at the AC input still play a role in surge and safety management, but they do not replace DC-side soft-start and inrush control. Detailed behaviour of AC input components and surge events is addressed in the “AC Input & EMI Front-End” page; this section focuses on DC-side control around adapter and PSU outputs.

SOA protection & fault profiles for MOSFETs

Safe operating area (SOA) defines how much voltage, current and time a MOSFET can tolerate without damage. In adapter and PSU applications, short circuits and heavy inrush events push the device close to its SOA limits. eFuse and Hot-Swap controllers are most effective when their current limits and fault timers are aligned with the SOA curves of the MOSFETs they drive.

A controlled short circuit with current limiting does not automatically guarantee safety. Instead of an immediate failure, the MOSFET spends time in a high Vds and high Id region where its dissipation is limited by time on the SOA plot. The protection task is therefore to allow enough time for benign overloads and inrush events, while cutting off sustained faults before the device accumulates more energy than its package and silicon can dissipate.

Fault profiles in PSUs can be grouped into hard shorts, overloads, capacitive inrush and repeated intermittent faults. Hard shorts produce very high current and high voltage stress and must be interrupted quickly. Overloads are lower in magnitude but last longer and can overheat devices if allowed to continue. Capacitive inrush produces a high current pulse of limited duration that should usually be tolerated during soft-start. Intermittent faults may not violate SOA in a single event but can accumulate thermal stress over time.

To manage these profiles, eFuse controllers combine several protection mechanisms. Thermal foldback reduces current as junction temperature rises, automatically derating the device under long events. I²t or energy monitoring integrates current over time to mimic thermal stress and triggers shutdown when a programmable threshold is exceeded. Fault timers define how long the device may remain in a current-limited state before declaring a fault, allowing normal inrush but blocking sustained shorts.

In a low-voltage adapter tail, where currents of 5–20 A at 12 V or 24 V are common, integrated eFuse devices in SO-8 or Power-QFN packages can protect the output stage, provided that current limits and timers respect the SOA curves in the datasheet. In server PSUs, where main bus currents reach 40–80 A and backplane capacitance is large, Hot-Swap controllers with external LFPAK, D²PAK or Power-QFN MOSFETs are typically required. Here, the SOA plot is used directly to choose allowable current and time combinations and to set conservative fault timers.

This section focuses on SOA management for low-voltage DC buses in power supplies and adapters. High-voltage traction or HVDC SOA design, including IGBT and SiC devices and multi-level protection stages, is handled in dedicated high-voltage topics.

Reverse blocking & ideal-diode behavior in adapters

Reverse blocking and ideal-diode behavior protect adapters and PSUs against unwanted backfeed from external sources and from other paralleled supplies. When an external battery, another PSU or a live backplane sits at the output side, reverse current can flow back into the adapter output stage if there is no controlled one-way path. In redundant systems, a failed module without reverse blocking can drag down healthy modules and compromise overall availability.

Ideal-diode control inside an eFuse or Hot-Swap controller replaces lossy Schottky OR-ing with an actively driven MOSFET. By monitoring the voltage difference between input and output and by sensing reverse current, the controller turns the MOSFET on when forward conduction is needed and turns it off quickly when the output tries to drive the input. This reduces conduction loss, limits reverse energy into sensitive circuitry and allows clean power-path handover between multiple sources.

Key parameters include the reverse current threshold, the reverse voltage threshold and associated hysteresis. A reverse current threshold that is too low reacts to harmless current sharing and noise, while a threshold that is too high exposes the adapter to large backfeed currents before protection engages. Reverse voltage hysteresis keeps the controller from chattering when two sources are nearly equal in voltage, and debounce or deglitch times filter out cable ringing and short disturbances that should not trigger repeated open–close cycles.

In multi-PSU systems, ideal-diode eFuse controllers act as the power-path layer underneath higher level power-sharing schemes. They ensure that a failed or disabled module does not sink current from active peers and that handover between modules happens smoothly when one supply takes over for another. In adapter-plus-battery architectures, ideal-diode controllers prevent the backup battery from feeding back into the adapter output stage while still allowing seamless transfer of load from adapter to battery when the adapter is removed or loses mains power.

This section focuses on low-voltage DC power-path behavior in adapters and PSUs. Protocol-level negotiation and role control for USB-C, including CC and PDO handling, and PoE PD signature and classification are covered in the dedicated “USB-C Power Path / Load Switch” and “PoE PD Module (802.3af/at/bt)” pages.

Telemetry, fault logging & PMBus hooks

Telemetry-enabled eFuse and Hot-Swap controllers turn protection from a black box into an observable node in the power system. Real-time measurements of current, voltage, power and temperature, combined with fault flags and counters, allow adapters, server PSUs and bench supplies to distinguish occasional misuse from persistent overloads and wiring problems. Exposing this data over I²C or PMBus links protection events directly into the digital control plane.

Typical registers include per-channel current and voltage readings, device temperature, warning and fault thresholds and fault status bits for overcurrent, short-circuit, overtemperature and reverse events. Many devices also maintain fault logs that capture the last fault type, the affected channel and a counter of how often each channel has tripped. These hooks let a Digital PSU Controller or system MCU record not just that a rail shut down, but why and how often it has happened.

In server PSUs, eFuse telemetry can be polled by a PMBus-based digital controller or by a baseboard management controller. When a rail consistently operates near its current limit, the controller can automatically derate the rail, increase fan speed or redistribute load across modules. When fault counters for a particular rail rise above a threshold, the power system can switch that rail to a latch-off recovery mode and raise a targeted alarm that points field technicians to the right connector or load.

Bench and programmable supplies use eFuse telemetry to build useful front-panel and PC GUI features. Real-time current and voltage readings can be plotted alongside OCP and SOA thresholds, while fault logs show exactly when and how a device under test drove a channel into protection. Engineers can then refine limit settings based on measured behaviour instead of guesswork, and can export fault histories as part of validation reports or field-return analysis.

PMBus command syntax, digital control-loop design and system-wide power sequencing remain the responsibility of the “Digital PSU Controller (PMBus)” page. This section focuses on how eFuse and Hot-Swap devices present telemetry and fault hooks that higher level controllers can use to implement derating, alarm and remote clear-latch strategies in adapters and PSUs.

Design checklist & IC role mapping

This section acts as a checklist for deciding whether a simple load switch, a full-featured eFuse or a multi-channel Hot-Swap controller is appropriate for an adapter or PSU rail. Working through the load type, electrical limits, SOA margin, protection modes and telemetry requirements helps prevent under-designed protection that only shows weaknesses after field deployment.

1. Load type & dynamic behaviour

Clarify what the eFuse or Hot-Swap device is actually driving:

• Purely capacitive load at the adapter or PSU output (large low-ESR bulk capacitors).
• Capacitive load plus long cables, introducing extra line inductance and additional charging transients.
• Motor or fan loads with high startup current and possible stall conditions.
• Electronic loads or DUTs with fast current steps, as in bench and programmable PSUs.

Simple load switches are suited mainly to lighter, non-critical loads with modest inrush. Large capacitive or motor-type loads often require full-featured eFuse or Hot-Swap controllers with defined soft-start and fault timing.

2. Voltage, current, inrush and start-up targets

Define the electrical envelope before choosing a device family:

• Input / bus voltage range for the protected rail (for example 5 V, 12 V, 24 V or 48 V).
• Maximum continuous load current and expected peak current in normal operation.
• Effective output capacitance and estimated peak inrush current during soft-start.
• Target start-up time and maximum acceptable dv/dt at the load.

These parameters determine whether an integrated MOSFET eFuse is sufficient or whether a controller with external MOSFETs is required. For example, a 12 V, 5 A adapter output with 1–2 mF of capacitance can often be handled by an integrated 10–15 A eFuse, whereas a 12 V, 60 A server bus usually demands a Hot-Swap controller driving one or more power MOSFETs.

3. SOA margin, R_DS(on) and thermal design

Check that the MOSFET safe operating area and thermal path can support both normal operation and worst-case faults:

• Verify that the product of limited current, bus voltage and fault time fits inside the MOSFET SOA curves.
• Confirm that the R_DS(on) and copper area keep conduction losses and temperature rise within budget.
• Allow additional SOA margin for repetitive faults and high ambient temperature conditions.
• For external MOSFETs, reserve layout area for thermal vias and multi-layer copper spreading.

Integrated eFuse solutions simplify SOA checks at moderate currents, while high-current Hot-Swap designs require explicit alignment between the controller fault timers and the MOSFET SOA charts.

4. Protection modes and restart policy

Decide how the rail should behave when protection triggers:

• Auto-retry for consumer adapters and chargers, where short faults are often benign.
• Latch-off for server and infrastructure PSUs, where repeated automatic restarts may stress connectors or wiring.
• Timed retry for bench supplies and programmable PSUs, to avoid continuous pulsing into a fault.
• Reverse blocking and ideal-diode behaviour where external sources or parallel PSUs are present.

The required protection policy strongly influences whether a minimal load switch is sufficient or a protection-oriented eFuse or Hot-Swap controller is needed.

5. Telemetry, fault logging and digital hooks

Clarify whether the rail must participate in digital monitoring and control:

• Is real-time current, voltage or temperature monitoring required?
• Must fault type and channel information be logged for service diagnostics?
• Should a PMBus controller, MCU or BMC be able to adjust limits or clear latch-off remotely?
• Is integration into existing health reporting dashboards a requirement?

If any of these answers are positive, a telemetry-capable eFuse or Hot-Swap device with I²C or PMBus access is preferred over a simple load switch or purely analog protection IC.

6. IC role mapping with example device families

Once the checklist items are defined, the rail can be mapped to an appropriate IC category. The examples below use generic device families and part numbers without tying to specific manufacturers.

6.1 Simple load switch (small, non-critical rails)

Use for low-current auxiliary rails, sensor supplies or logic rails where inrush is modest and no telemetry is required.

• Typical range: 0.5–2 A, 1.8–5.5 V or 3.3–12 V.
• Examples of part numbers: TPS22918, TPS22965, AP22802.
• Protection: basic slew-rate control and overcurrent shutdown, no SOA shaping or reverse blocking.

6.2 Full-featured eFuse with integrated MOSFET

Use for adapter outputs, mid-current PSU rails and protected backplane feeds where soft-start, current limiting and reverse protection are required.

• Typical range: 3.3–24 V, 3–15 A per channel.
• Examples of part numbers: TPS25940, TPS25982, LTC4365, TPS26600.
• Features: programmable current limit and dv/dt, fault timers, reverse blocking and in some cases basic telemetry.
• Use in 65–300 W adapters, 12 V and 24 V rails in industrial PSUs and protected outputs in bench supplies.

6.3 Multi-channel Hot-Swap controller with external MOSFETs

Use for high-current server and telecom backplanes, where modules are hot-plugged and bus currents reach tens of amperes per slot.

• Typical range: 9–80 V buses, 20–80 A per channel using external power MOSFETs.
• Examples of part numbers: LM5069, LTC4215, LTC4357, LTC4368.
• Features: gate control for external MOSFETs, programmable inrush and fault timing, support for paralleling devices, and often dedicated ideal-diode or OR-ing control.
• Frequently paired with MOSFETs in LFPAK, D²PAK or Power-QFN packages chosen directly from SOA requirements.

Entry-level rails can often use simple load switches. As current, inrush and availability requirements rise, designs move to integrated eFuse devices and finally to Hot-Swap controllers with external MOSFETs that are sized explicitly for SOA and thermal performance.

Layout, sensing & thermal hints for PSU eFuses

Layout quality determines how closely an eFuse or Hot-Swap circuit matches its datasheet performance. High-current copper paths, Kelvin sense routing and thermal spreading around the MOSFET and shunt resistor all contribute to accurate protection and predictable derating. A careful PCB arrangement reduces nuisance trips, improves SOA margin and avoids hotspots that erode reliability.

1. High-current paths and copper planning

The protected path from input connector through the eFuse MOSFET and into the output bus should be short and wide. Large loop areas increase inductance and aggravate voltage overshoot during fast faults. Use solid copper pours on multiple layers, with stitched vias near package pins, to spread current and reduce both resistive drop and temperature rise.

• Place the eFuse or Hot-Swap device close to the input connector or backplane finger.
• Keep the main current path straight, avoiding sharp corners and unnecessary neck-downs.
• Use via arrays near high-current pins to tie top and inner layer copper together.
• Ensure return paths are as short as possible to minimise loop inductance.

2. Shunt placement and Kelvin sensing

Accurate current limiting depends on clean sensing. The sense resistor or sense element should sit directly in the main current path, with dedicated Kelvin traces routed separately from the power copper. Taking sense connections from the ends of a wide pour, rather than from the resistor pads, injects error from IR drop and can make the current limit appear higher or lower than intended.

• Place the shunt resistor close to the eFuse IC or Hot-Swap controller, avoiding long stubs.
• Route a tightly coupled pair of Kelvin traces from the sense pins directly to the shunt pads.
• Keep Kelvin traces away from switching nodes and high dv/dt edges to minimise noise pickup.
• For multi-channel devices, separate sense loops spatially to avoid crosstalk between channels.

3. Thermal coupling and hotspot management

The MOSFET inside an eFuse or the external MOSFET in a Hot-Swap design is usually the dominant heat source. Thermal spreading copper, via arrays under the drain or source pads and separation from other hot components help keep junction temperatures under control. Nearby electrolytic capacitors should be placed so that their lifetime is not limited by MOSFET heat.

• Use large copper regions on multiple layers tied to the MOSFET thermal pads with dense vias.
• Keep high-dissipation shunts and MOSFETs away from temperature-sensitive electrolytic capacitors.
• Place temperature-sense points where they best represent device junction temperature, not at the coolest corner.
• Consider airflow direction when deciding which edge of the board should host the hottest components.

4. Derating and interaction with system thermal control

Many eFuse and Hot-Swap devices include internal temperature sensing or thermal foldback functions. These readings indicate local device stress rather than full-system temperature. When used alongside a digital PSU controller, they can inform derating policies that reduce current limits or redistribute load before thermal shutdown is reached.

Detailed fan control, airflow design and system derating curves belong to the “Thermal & Fan Control” topic. The focus here is to ensure the eFuse and its current-sense elements are laid out and cooled in a way that makes thermal protection repeatable and predictable.

Application mini-stories for PSU eFuses & Hot-Swap

These application mini-stories show how eFuse and Hot-Swap controllers are placed in real adapters and PSUs. Each example links soft-start, SOA protection, reverse blocking and telemetry to practical behaviour at the connector and at the monitoring interface, without leaving the adapter and PSU domain.

Story A · 65 W USB-C PD adapter output protection

A 65 W USB-C PD adapter delivers multiple PDOs up to 20 V at 3 A or higher. At the Type-C connector, rapid load steps and occasional short circuits are common when users plug in unknown cables and devices. Without a dedicated eFuse at the VBUS pin, the combination of bulk output capacitors, cable inductance and fast load transients can overstress the connector pins, output MOSFETs and transient protection components, leading to intermittent failures that are difficult to classify in field returns.

Placing a full-featured eFuse between the regulated secondary output and the USB-C VBUS pin creates a controlled power path layer under the PD and CC protocol logic. The current limit is set slightly above the maximum negotiated PD current, with a dv/dt-controlled soft-start that charges cable and device input capacitance without overshoot. Fault timers and SOA margin are chosen so that hard shorts at the connector are clamped to a defined current for a short and safe interval before the eFuse shuts off, keeping the MOSFET inside its safe operating area while giving the PD controller time to abort the contract if needed. Reverse blocking prevents external battery packs or another powered source on the USB-C side from backfeeding into the adapter output stage.

Telemetry-enabled variants add clear visibility into connector stress. The eFuse counts how many times overcurrent, short-circuit or reverse events have occurred on that port and records the last fault type. During production test or failure analysis, a service fixture reads these counters over I²C and correlates them with field return data, revealing whether most damaged units experienced repeated short circuits, sustained overloads or abnormal backfeed events. USB-C protocol handling, PDO negotiation and CC role control remain the responsibility of the dedicated “USB-C PD/QC/PPS Controller” and “USB-C Power Path / Load Switch” functions, while the eFuse focuses on the physical VBUS power path at the adapter side.

• Placement: between regulated secondary output and USB-C VBUS pin.
• Focus: soft-start, hard short protection and reverse blocking at the connector.
• Benefit: connector failures translated into countable short / overload / reverse events.

Story B · 1U server PSU module hot-swap and backplane protection

A 1U server PSU feeds a shared DC backplane in an N+1 or N+N redundant configuration. Multiple modules operate in parallel, and servers are expected to remain online while modules are inserted, removed or replaced. Without a Hot-Swap controller and ideal-diode behaviour at each module input, the backplane can see uncontrolled inrush currents when a new module is plugged in, and a failed module can sink current from the bus, dragging down healthy peers and destabilising the system.

In a robust design, the rectified and regulated DC output of each PSU module feeds a Hot-Swap controller that drives one or more external MOSFETs in series with the module’s backplane finger. The controller shapes inrush current into the backplane capacitance, using a programmable current limit and gate ramp to keep di/dt under control and maintain the MOSFET inside its SOA envelope. Ideal-diode or OR-ing control ensures that when a module is disabled or fails low, the MOSFET turns off quickly and prevents the shared bus from backfeeding into the faulty module. Parallel MOSFETs and careful SOA checking allow high slot currents without compromising reliability.

The Hot-Swap device exposes fault flags, per-slot fault counters and sometimes basic telemetry over an internal serial interface to the module’s Digital PSU Controller. That controller, in turn, reports slot health and fault history over PMBus to the chassis management controller. System firmware can then mark a particular module as “degraded” after repeated inrush or overcurrent faults, automatically switch its protection mode to latch-off and prompt operators to replace it at the next maintenance window. Detailed PMBus command mapping and system-wide sequencing remain topics for the “Digital PSU Controller (PMBus)” page; this story focuses on how Hot-Swap and ideal-diode control at the module boundary protect the backplane and provide precise fault localisation.

• Placement: between module DC output and backplane finger.
• Focus: controlled inrush, ideal-diode isolation and slot-level fault visibility.
• Benefit: backplane protection and clear identification of weak or failing modules.

Story C · Bench PSU channel with programmable protection and logging

A bench or programmable PSU channel is used to power prototypes and devices under test, often at adjustable voltage and current limits. Engineers deliberately apply short circuits, overload the output and test protection behaviour while monitoring the device. Traditional designs rely on analog overcurrent comparators and relays that may react differently across units, offer limited configurability and provide very little information beyond “the output shut off”.

In a more instrument-grade approach, the programmable DC/DC stage sets the desired voltage and current window, while an eFuse sits between that stage and the output binding posts. The eFuse enforces a hard ceiling for current and, if needed, a foldback profile that limits energy into a fault. Its fault timer and SOA-aware protection ensure that repeated short-circuit testing does not overstress the internal MOSFET or output wiring. The PSU channel controller configures the eFuse’s current limit and protection mode to match each test profile, so that the instrument can emulate different OCP behaviours while still being protected by a consistent hardware safety layer.

Telemetry turns the eFuse into a source of rich status information. Each time a short-circuit, overcurrent or thermal event occurs, the eFuse sets status bits and optionally records the channel and fault type. The bench PSU’s MCU reads these registers over I²C or PMBus and drives front-panel indicators such as “OCP” and “Over Power”, along with numeric messages indicating which channel tripped and at what current. On the PC GUI side, fault histories can be logged and exported with test reports, allowing engineers to show, for example, how many OCP events occurred during a given stress test. The underlying DC/DC loop design and communication interface belong to other topics; here the focus is on using an eFuse as a repeatable, instrument-grade protection block with built-in observability.

• Placement: between programmable DC/DC stage and output terminals.
• Focus: programmable current limit, foldback and event logging.
• Benefit: consistent protection behaviour and exportable OCP/OPP event history.

FAQs about eFuse & Hot-Swap in power supplies