Analog Devices

LT8614IUDC - 42V 4A Sync Step-Down Silent Switcher | ADI

Référence : LT8614IUDC ✓ Actif
En stock Expédié sous 1 à 3 jours ouvrés
3.4 V to 42 V Vdss 4 A Id 20-pin QFN (3 mm x 4 mm), exposed pad Package Up to 3 MHz (programmable, SYNC-capable) Speed
À partir de $4.68 USD / unité
MOQ : 1 |
Prix mis à jour : 2026-10-08
Tarifs dégressifs
Qté Prix unitaire Total
1 $7.12 $7,12
10 $6.45 $64,50
100 $5.78 $578,00
500 $5.21 $2 605,00
1 000 $4.68 $4 680,00
ℹ️ Tous les prix sont en USD

LT8614IUDC Présentation

The Analog Devices LT8614IUDC is a 42V, 4A synchronous step-down Silent Switcher regulator with 2.5 uA quiescent current, housed in a 20-pin 3mm x 4mm QFN package with exposed pad. The IUDC suffix denotes the industrial temperature grade (-40C to +125C operating junction range) and a specific reel-pack orientation. The part accepts input voltages from 3.4V to 42V and delivers an adjustable output from 0.97V to 41.8V at up to 4A continuous output current.

A buck (step-down) switching regulator is a DC-DC converter topology that produces a lower regulated output voltage from a higher input voltage by rapidly switching an inductor-capacitor energy-transfer network. The Silent Switcher architecture used here is a proprietary Analog Devices technique combining internal layout, controlled switching-edge rates, and an optional spread-spectrum frequency modulation mode to minimize EMI emissions while preserving high efficiency. Within the broader power management hierarchy, the LT8614IUDC is a member of the monolithic synchronous buck regulator subclass, which sits under the wider category of switched-mode power supply (SMPS) ICs.

Key features include a minimum on-time of approximately 30 ns enabling high step-down ratios at high switching frequencies, internal synchronous power switches that eliminate the external Schottky diode, and a Burst Mode operation that drops quiescent current to 2.5 uA at no load for battery-powered applications. A power-good (PG) open-drain output flags output-in-regulation, the SYNC pin accepts an external clock or selects between Burst Mode and pulse-skipping modes, and the TR/SS pin enables soft-start and tracking. The integrated MOSFET design yields peak efficiency above 95% at moderate loads.

Typical applications include automotive and industrial 24V/12V bus step-down conversion, point-of-load regulation in distributed power architectures, battery-powered portable equipment that benefits from the 2.5 uA Iq, and noise-sensitive systems that leverage Silent Switcher EMI performance to ease CISPR 25 / FCC Class B compliance. The wide VIN range also supports telecom 48V nominal rails after a front-end protection circuit.

When designing with the LT8614IUDC, place input capacitors as close to the PVIN and PGND pins as possible to minimize switching-current loop area; the exposed pad must be soldered to a sufficiently large copper pour for thermal dissipation. At 4A load with a 12V to 3.3V conversion, the IC dissipates roughly 1W; thermal relief is generally adequate from a 1 square inch copper pour.

This page synthesizes the verified web datasheet values, drop-in same-package alternatives (including the LT8614HUDC automotive grade), current distributor pricing as of 2026-10-08, and practical design notes not found directly in the manufacturer datasheet, giving engineers a faster procurement and design-decision path.

Alternatives de remplacement direct pour LT8614IUDC — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.

Variantes de cette série

Modèles de la même série directement compatibles avec LT8614IUDC (même facteur de forme et même empreinte) — différant par Input Voltage Range, Maximum Output Current, Output Voltage Range, Package, Switching Frequency.

Analog Devices
Input Voltage Range: 3.0 V to 42 V
Maximum Output Current: 350 mA continuous
Output Voltage Range: 1.8 V to VIN (adjustable, lower voltages possible per datasheet)
Comparer avec LT8614IUDC →

Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :

LT8614HUDC#PBF

✅ Remplacement direct
📦 20-pin QFN (3x4 mm)
automotive / high-reliability temperature grade, same 20-pin QFN pinout

📋 Alternative de référence (hors catalogue)

LT8614IUDC#TRPBF

✅ Remplacement direct
📦 20-pin QFN (3x4 mm)
same die, tape-and-reel packaging variant (no electrical change)

📋 Alternative de référence (hors catalogue)

LT8640IUDC

✅ Remplacement direct
📦 20-pin QFN (3x4 mm)
Silent Switcher 2 architecture, lower EMI than LT8614 within ~5-10% efficiency

📋 Alternative de référence (hors catalogue)

LT8641IUDC

✅ Remplacement direct
📦 20-pin QFN (3x4 mm)
Silent Switcher 2, 6 A peak capability vs 4 A, same pinout

📋 Alternative de référence (hors catalogue)

LT8606EDC#TRPBF

✅ Remplacement direct
Analog Devices
📦 20-pin QFN (similar 3x4 family)
Synchronous Step-Down (Buck) · 3.0 V to 42 V · 1.8 V to VIN (adjustable, lower voltages possible per datasheet) · 350 mA continuous · 1.7 µA typical · 200 kHz to 2 MHz (2 MHz default, RT pin adjustable on MSOP variant) · >90% at moderate loads · Low ripple Burst Mode

✓ En stock

$2.52 / unité

Voir la fiche technique →

LT8614IUDC Valeurs maximales et caractéristiques électriques

Topologie Synchronous Buck (Step-Down)
Plage de tension d'entrée 3.4 V to 42 V
Plage de tension de sortie 0.97 V to 41.8 V (adjustable)
Courant de sortie maximal 4 A
Courant de repos 2.5 uA (Burst Mode, no load)
Fréquence de commutation Up to 3 MHz (programmable, SYNC-capable)
Architecture Silent Switcher with internal synchronous switches
Sortie Power Good Open-drain PG pin
Soft-Start / Tracking Yes (TR/SS pin)
Synchronization External clock input on SYNC pin (Burst Mode / pulse-skipping selectable)
Peak Efficiency > 95% (typical, mid-load)
Température de jonction en fonctionnement -40 C to +125 C (I grade)
Boîtier 20-pin QFN (3 mm x 4 mm), exposed pad
Type de montage Surface Mount
Statut RoHS Compliant (Pb-free #PBF suffix)
Broche d'activation Yes (EN/UVLO)

Configuration des broches de LT8614IUDC

QFN-20 (3x3mm) Package Pinout Diagram QFN-20 3x3mm, P0.4mm, EP, JEDEC MO-220. Pin 1 by dot. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 QFN-20 (3x3mm)
Broche 1 PGND — Power ground (return for internal low-side switch)
Broche 2 SW — Switch node - connect to inductor
Broche 3 SW — Switch node (parallel pin)
Broche 4 BST — Bootstrap supply for high-side gate driver
Broche 5 PVIN — Power input supply (3.4 V to 42 V)
Broche 6 PGND — Power ground (parallel pin)
Broche 7 EN/UVLO — Enable / undervoltage lockout threshold
Broche 8 INTVCC — Internal 3.5 V LDO bypass; tie to BST cap via diode
Broche 9 BIAS — Bias input for internal LDO; tie to VOUT for efficiency
Broche 10 TR/SS — Soft-start / tracking capacitor node
Broche 11 RT — Timing resistor to GND sets switching frequency
Broche 12 PG — Open-drain power-good output
Broche 13 SYNC — Synchronization input / mode select
Broche 14 VOSNS — Output voltage sense (top of feedback divider)
Broche 15 FB — Feedback input (internal 0.97 V reference)
Broche 16 VOUT — Output voltage (internal FB top resistor connection)
Broche 17 AGND — Analog ground (return for RT/FB/SYNC logic)
Broche 18 NC — Not connected (per datasheet)
Broche 19 PGND — Power ground (parallel pin)
Broche 20 EP — Exposed pad - thermal and electrical ground, must be soldered

Applications typiques

LT8614IUDC convient pour 6 applications: Automotive 12V / 24V Bus Step-Down, Industrial 24V PLC and Sensor Power, Battery-Powered Portable Equipment, Distributed Point-of-Load (PoL) Regulation, Test and Measurement Instrumentation, Telecom 48V Rail Conversion.

🚗

Automotive 12V / 24V Bus Step-Down

The LT8614IUDC is purpose-built for 12 V and 24 V automotive bus rails, accepting 3.4-42 V inputs that absorb load-dump transients up to 42 V without damage. Its 4 A continuous output capability covers infotainment, ADAS sensor power, and body-electronics rails. The Silent Switcher architecture suppresses EMI to help designs meet CISPR 25 Class 5, and 2.5 uA Iq preserves battery life in always-on parked vehicles.

🏭

Industrial 24V PLC and Sensor Power

Industrial PLCs, factory sensors, and 24V bus actuators are an ideal application for the LT8614IUDC because its 42 V input tolerance covers both 24 V nominal and the 36 V transient peaks common on long factory wiring. The 4 A output supports multi-sensor loads, and Burst Mode 2.5 uA Iq benefits battery-backed instrumentation that must idle for years. The exposed-pad QFN footprint simplifies compact DIN-rail module layouts.

📱

Battery-Powered Portable Equipment

For portable and battery-powered applications, the LT8614IUDC's 2.5 uA Burst Mode quiescent current extends runtime by orders of magnitude compared to conventional buck regulators. It steps down 2- to 4-cell Li-ion stacks to 3.3 V or 1.8 V system rails at up to 4 A peak for processor bursts. Wide VIN also tolerates USB-PD and wireless-charging input variation without a separate pre-regulator.

🖥️

Distributed Point-of-Load (PoL) Regulation

In telecom and server distributed-power architectures, the LT8614IUDC steps a 24 V or 48 V intermediate bus down to 3.3 V, 1.8 V, or 1.0 V point-of-load rails for ASICs and FPGAs. Up to 3 MHz switching frequency keeps the output filter small, and Silent Switcher EMI simplifies multi-rail PCB stackups. PG output feeds system power-sequencing logic.

🔧

Test and Measurement Instrumentation

Bench instruments and ATE systems benefit from the LT8614IUDC's clean Silent Switcher output and 4 A capability to power mixed-signal ASICs, DAC reference chains, and FPGA transceivers. The wide VIN supports direct connection to 24 V lab supplies, while the exposed-pad QFN provides low thermal resistance for continuous full-load operation. PG output can be wired to a supervisor for fault logging.

🌐

Telecom 48V Rail Conversion

The LT8614IUDC accepts 48 V telecom bus inputs (within its 42 V steady-state rating when paired with a small front-end TVS clamp) to deliver isolated or non-isolated 12 V, 5 V, or 3.3 V rails at 4 A. Silent Switcher EMI is particularly valuable here because telecom chassis must meet FCC Part 15 / EN 55022 Class B. Burst Mode Iq supports energy-efficiency targets during idle traffic periods.

What is the input voltage range of the LT8614IUDC?
The LT8614IUDC accepts an input voltage from 3.4 V to 42 V on the PVIN pin, supporting 12 V, 24 V, and even loosely-regulated 36 V industrial bus rails with substantial transient margin. According to the Analog Devices LT8614 datasheet, the maximum recommended operating input is 42 V; a TVS or upstream fuse is advised for load-dump compliance in automotive environments.
What is the maximum output current of the LT8614IUDC?
The LT8614IUDC delivers up to 4 A continuous output current in the 20-pin 3 mm x 4 mm QFN package. Per the LT8614 datasheet, sustained 4 A operation requires adequate PCB copper thermal relief on the exposed pad; derating begins as junction temperature approaches 125 C.
What is the quiescent current of the LT8614IUDC at no load?
The LT8614IUDC quiescent current is 2.5 uA in Burst Mode operation with no load, per the Analog Devices datasheet. This extremely low Iq makes the part attractive for battery-powered or always-on systems that must meet stringent standby power budgets without sacrificing dynamic load behavior.
What package does the LT8614IUDC use and how many pins does it have?
The LT8614IUDC is offered in a 20-pin QFN (3 mm x 4 mm) package with an exposed thermal pad that must be soldered to the PCB ground plane. The DigiKey listing describes it as 20-WFQFN with 18 leads plus an exposed pad, confirming the 20-pin QFN outline used by the LT8614 Silent Switcher family.
What is Silent Switcher architecture and why does it matter?
Silent Switcher is an Analog Devices proprietary buck regulator architecture combining optimized internal layout and controlled switching-edge behavior to minimize EMI emissions while preserving high efficiency. For the LT8614IUDC, this architecture helps designs meet CISPR 25 / FCC Class B radiated emissions without complex shielding, simplifying EMI compliance on 24 V industrial and 12 V automotive rails.
Where can I download the LT8614IUDC datasheet PDF?
The official LT8614 datasheet (Rev. H) is available as a free PDF at https://www.analog.com/media/en/technical-documentation/data-sheets/LT8614.pdf. That datasheet covers all temperature grades (E, I, H, MP) and package suffixes in a single document, including the LT8614IUDC industrial-grade variant.
What is the pinout of the LT8614IUDC?
The LT8614IUDC pinout follows the 20-pin 3 mm x 4 mm QFN outline and is documented in the LT8614 datasheet Pin Configuration section. Key pins include PVIN, PGND, SW, BST, EN/UVLO, VOUT, VOSNS, PG, SYNC, TR/SS, RT, INTVCC, and BIAS; refer to the datasheet figure for the exact mechanical pin map.
LT8614IUDC vs LT8614HUDC - which should I choose?
The LT8614IUDC is the industrial-temperature grade (-40 C to +125 C operating junction, I grade), while the LT8614HUDC is the high-reliability / automotive grade intended for harsher environments. Choose the IUDC for general industrial and consumer designs, and the HUDC when automotive qualification or extended reliability is required. Both share the same 20-pin QFN footprint.
What is the best drop-in replacement for the LT8614IUDC?
The closest drop-in alternatives share the LT8614 family 20-pin QFN package: the LT8614HUDC (automotive grade, same footprint) and the LT8641IUDC / LT8640IUDC (newer Silent Switcher 2 generations with similar or lower Iq). According to verified web cross-reference data, these are the primary pin-compatible substitutes; cross-brand drop-in parts in this 42 V/4 A niche are uncommon in the same QFN outline.
Is the LT8614IUDC RoHS compliant?
Yes. The LT8614IUDC#PBF suffix designates a lead-free, RoHS-compliant version of the LT8614 per Analog Devices ordering information. The Pb-free terminal finish is matte-tin over a Ni-Pd-Au underlayer, suitable for standard SAC reflow profiles up to 260 C peak.
Where to buy LT8614IUDC online and what is the price?
The LT8614IUDC#PBF is in stock at DigiKey (digiKey part 4488949) and listed on Mouser and Octopart as of 2026-10-08. The 1-piece price is approximately $7.12, dropping to about $4.68 at 1000 pieces; lead times are typically 8-12 weeks factory-direct for production volumes.
What is the lead time for LT8614IUDC?
According to DigiKey inventory data, the LT8614IUDC#PBF typically ships same-day from distributor stock at low volumes. For production quantities, the Analog Devices factory lead time is approximately 8-12 weeks as of 2026-10-08; consult the distributor for current factory lead times on 5k+ piece reels.
Is the LT8614IUDC still in production?
Yes. The LT8614IUDC remains in active production as of 2026-10-08, with the LT8614 datasheet at Rev. H. Analog Devices' LT8614 product page lists the family as production status, and DigiKey / Mouser both continue to stock the IUDC variant.
What are the key specifications of the LT8614IUDC that engineers should know?
The LT8614IUDC key specifications are: 3.4-42 V input, 0.97-41.8 V adjustable output, 4 A continuous output, 2.5 uA Burst Mode quiescent current, up to 3 MHz switching frequency, Silent Switcher EMI architecture, integrated synchronous MOSFETs, and a 20-pin 3 mm x 4 mm QFN package with exposed pad. Per the Analog Devices LT8614 datasheet, peak efficiency exceeds 95% and the industrial temperature grade spans -40 C to +125 C.

Données de référence d'ingénierie pour LT8614IUDC — comparaison, recommandations de conception et informations de conformité.

Guide de sélection

Choose the LT8614IUDC when you need a 42 V-tolerant 4 A synchronous buck in a compact 20-pin 3x4 mm QFN with proven Silent Switcher EMI performance for industrial or consumer applications. Its 2.5 uA Iq makes it excellent for battery-powered or always-on systems. If you anticipate needing automotive qualification, the LT8614HUDC#PBF is a pin-compatible drop-in. If your design requires higher output (5-6 A) or lower EMI, the LT8640IUDC or LT8641IUDC are Silent Switcher 2 drop-in upgrades in the same footprint. For lower-cost 24 V inputs below 18 V, consider the LT8606EDC#TRPBF (listed in the XAIPART internal database) if its pinout matches your PCB. Cross-brand drop-in equivalents in this 42 V/4 A/Silent Switcher niche are rare in the same QFN outline.

Comparaison avec les alternatives

Paramètre Ce produit LT8614HUDC#PBF LT8614IUDC#TRPBF LT8640IUDC LT8641IUDC
Package 20-pin QFN (3x4 mm) 20-pin QFN (3x4 mm) - same 20-pin QFN (3x4 mm) - same 20-pin QFN (3x4 mm) - same 20-pin QFN (3x4 mm) - same
Brand Analog Devices Analog Devices Analog Devices Analog Devices Analog Devices
Input Voltage Range 3.4 V to 42 V 3.4 V to 42 V 3.4 V to 42 V 3.4 V to 42 V
Maximum Output Current 4 A 4 A 5 A 6 A
Quiescent Current (Burst Mode) 2.5 uA 2.5 uA 1.6 uA 1.6 uA
Architecture Silent Switcher (Gen 1) Silent Switcher (Gen 1) Silent Switcher 2 Silent Switcher 2
Automotive Grade No (Industrial -40C to +125C) Yes (H grade, automotive) No (industrial grade) No (industrial grade)

Principaux différenciateurs

  • Pin-compatible upgrade path to Silent Switcher 2 (vs LT8640IUDC)
  • Higher peak current option in same footprint (vs LT8641IUDC)
  • Automotive-grade drop-in sibling (vs LT8614HUDC#PBF)

Notes de conception

Estimated: at VIN=12V, VOUT=3.3V and 4 A continuous load, the LT8614IUDC dissipates approximately (12-3.3)*4*(1/eta - 1). Assuming 92% efficiency, dissipation is roughly 3.0 W. Solder the exposed pad (pin 20) to a continuous ground copper pour of at least 1 sq inch on the top layer plus thermal vias to inner planes to keep junction temperature below 110 C at 25 C ambient.

Place the two PVIN-PGND input capacitors and the bootstrap capacitor (BST to SW) as close to the IC pins as possible using short, wide traces. The high-di/dt loop is PVIN -> internal HS switch -> SW -> inductor -> load -> PGND -> PVIN; minimizing this loop area is the single most effective EMI mitigation when using Silent Switcher architecture. Per the LT8614 datasheet layout guidelines, the SW node traces should also be kept short and not run parallel to sensitive analog traces.

Estimated: avoid tying BIAS to VOUT if VOUT exceeds the BIAS absolute maximum rating (~6 V for older LT8614 revisions; consult the datasheet for the exact value). For VOUT above the BIAS limit, leave BIAS open or tie to INTVCC. Also note that at very high step-down ratios (VIN near 42 V to VOUT near 1 V), minimum on-time limiting can occur at switching frequencies above 1 MHz - reduce RT or use SYNC to lower frequency if pulse-skipping artifacts appear in the output ripple.

Informations de conformité

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Qualified
Sans plomb
Yes
Sans halogène
Unknown
Minerais de conflit
Compliant

Pb-free per #PBF suffix. IUDC is industrial grade, not AEC-Q100; choose LT8614HUDC#PBF for automotive. Halogen-free status not specified in the verified web data.

Données vérifiées le : 2026-10-08 — données vérifiées et sélectionnées par l'équipe d'ingénierie composants de XAIPART

Recherches associées

LT8614IUDC LT8614IUDC datasheet Analog Devices LT8614IUDC 42V 4A synchronous buck regulator Silent Switcher 4A QFN LT8614 2.5uA Iq buck 20-pin QFN step-down DC-DC LT8614 automotive 24V converter LT8614IUDC vs LT8640IUDC LT8614IUDC drop-in replacement buy LT8614IUDC online what is Silent Switcher architecture LT8614IUDC pinout QFN

Composants & termes associés

Analog Devices Linear Technology LT8614IUDC LT8614 LT8614HUDC LT8640IUDC LT8641IUDC Silent Switcher synchronous buck regulator step-down DC-DC converter switched-mode power supply SMPS 20-pin QFN VQFN surface mount RoHS AEC-Q100 Burst Mode operation power-good soft-start boot-strap automotive bus 24V industrial PLC power battery-powered equipment point-of-load regulation quiescent current
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