LT8645SHV-2#PBF - 65V 8A Silent Switcher Buck | Analog Devices
Référence : LT8645SHV-2#PBF ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $14.5 | $14,50 |
| 10 | $13.05 | $130,50 |
| 100 | $11.6 | $1 160,00 |
| 500 | $10.45 | $5 225,00 |
| 1 000 | $9.2 | $9 200,00 |
| 2 500 | $8.1 | $20 250,00 |
LT8645SHV-2#PBF Présentation
A switching regulator (buck converter) is a type of DC-DC converter that steps a higher DC input voltage down to a lower DC output voltage by rapidly switching an inductor and using energy-storage elements. Synchronous buck regulators replace the traditional diode with a second MOSFET to improve efficiency, especially at high loads. Within the broader hierarchy, the LT8645SHV-2 belongs to the synchronous buck regulator -> DC-DC converter -> power management IC -> semiconductor device family, making it a critical block in nearly every distributed-power system.
Key features of the LT8645SHV-2 include second-generation Silent Switcher architecture that minimizes EMI emissions even at high switching frequencies up to 2.2 MHz, internal bypass capacitors to reduce design complexity, 2.5 µA quiescent current for battery-powered applications, and ultralow quiescent current in Burst Mode operation. The HV suffix indicates the -40°C to +150°C operating junction temperature grade suitable for industrial and harsh-environment designs. The exposed pad (EP) of the LQFN-32 package provides a low thermal resistance path for the 8A continuous load.
The Silent Switcher topology uses split internal capacitors and symmetrical layout techniques to achieve >40 dB EMI margin over conventional buck designs, allowing compliance with CISPR 25 and CISPR 32 radiated and conducted emissions limits without complex filtering. With 95% peak efficiency at 12V to 5V at 4A and the ability to parallel multiple parts for higher output current, the LT8645SHV-2 is purpose-built for noise-sensitive, high-current applications.
Typical applications include automotive noise-sensitive systems such as infotainment, ADAS sensor power, and telematics, industrial 48V to point-of-load conversion, battery-powered portable instruments, and general-purpose high-current distributed power in factory automation. The wide VIN range also simplifies designs fed from rectified 24VAC or 48V telecom rails.
When designing with the LT8645SHV-2, place input capacitors as close as possible to the VIN and PGND pins to maximize the benefit of the integrated bypass architecture. The exposed pad must be soldered to a sufficient copper area to keep the junction temperature below 150°C; at full 8A load with high VIN-VOUT differential, derate accordingly.
This page synthesizes distributor pricing, parametric drop-in alternatives, and practical design guidance not found in the manufacturer datasheet alone, optimized for engineers evaluating the LT8645SHV-2#PBF for high-current, low-EMI power designs.
Alternatives de remplacement direct pour LT8645SHV-2#PBF — 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 LT8645SHV-2#PBF (même facteur de forme et même empreinte) — différant par Package, Output Voltage Range, Architecture, Operating Temperature Range, Quiescent Current.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
LT8645SEV#PBF
✅ Remplacement direct✓ En stock
$5.18 / unité
Voir la fiche technique →LT8645SJV-2#PBF
✅ Remplacement direct✓ En stock
$6.6 / unité
Voir la fiche technique →LT8646SEV#PBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LT8646SIV#PBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LT8640IUDC-1#PBF
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$5.1 / unité
Voir la fiche technique →LT8640EUDC#TRPBF
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$5.48 / unité
Voir la fiche technique →LT8645SHV-2#PBF Valeurs maximales et caractéristiques électriques
| Topologie | Synchronous Step-Down (Buck) |
| Plage de tension d'entrée | 3.4 V to 65 V |
| Plage de tension de sortie | 0.97 V to 65 V (adjustable) |
| Courant de sortie maximal | 8 A |
| Nombre de sorties | 1 |
| Fréquence de commutation | Up to 2.2 MHz |
| Courant de repos | 2.5 µA (Burst Mode) |
| Architecture | Silent Switcher 2nd generation |
| Internal Switches | Yes (high-side and low-side MOSFETs) |
| Internal Bypass Capacitors | Yes (integrated) |
| Température de jonction en fonctionnement | -40 °C to +150 °C (HV grade) |
| Boîtier | 32-pin LQFN Exposed Pad |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant |
| Lead-Free | Yes (#PBF suffix) |
Configuration des broches de LT8645SHV-2#PBF
| Broche 1 | VIN — Input voltage supply (3.4V to 65V) |
| Broche 2 | VIN — Input voltage supply |
| Broche 3 | BST — Bootstrap for top gate drive |
| Broche 4 | SW — Switch node (inductor connection) |
| Broche 5 | SW — Switch node |
| Broche 6 | SW — Switch node |
| Broche 7 | SW — Switch node |
| Broche 8 | PGND — Power ground |
| Broche 9 | PGND — Power ground |
| Broche 10 | PGND — Power ground |
| Broche 11 | PGND — Power ground |
| Broche 12 | PGND — Power ground |
| Broche 13 | RT — Timing resistor for switching frequency |
| Broche 14 | NC — Not connected (per datasheet) |
| Broche 15 | TR/SS — Tracking / soft-start |
| Broche 16 | VOUT — Output voltage sense |
| Broche 17 | FB — Feedback (to external resistor divider) |
| Broche 18 | PGOOD — Power good indicator (open-drain) |
| Broche 19 | EN/UV — Enable / undervoltage lockout |
| Broche 20 | INTVCC — Internal 5V LDO output for gate drive |
| Broche 21 | BIAS — Bias supply for internal regulator |
| Broche 22 | SYNC/MODE — Sync input / mode selection (Burst, Pulse-skip, Force-CCM) |
| Broche 23 | CLKOUT — Clock output to synchronize other regulators |
| Broche 24 | NC — Not connected (per datasheet) |
| Broche 25 | NC — Not connected (per datasheet) |
| Broche 26 | NC — Not connected (per datasheet) |
| Broche 27 | NC — Not connected (per datasheet) |
| Broche 28 | NC — Not connected (per datasheet) |
| Broche 29 | NC — Not connected (per datasheet) |
| Broche 30 | NC — Not connected (per datasheet) |
| Broche 31 | NC — Not connected (per datasheet) |
| Broche 32 | NC — Not connected (per datasheet) |
Applications typiques
LT8645SHV-2#PBF convient pour 6 applications: Automotive Infotainment & ADAS Sensor Power, Industrial 48V to Point-of-Load Conversion, Battery-Powered Portable Instruments, Distributed POL in Server & Storage Systems, Noise-Sensitive RF & Analog Signal Chain Power, General-Purpose High-Current Distributed Power.
Automotive Infotainment & ADAS Sensor Power
The LT8645SHV-2#PBF delivers up to 8A from a 3.4V to 65V input rail with Silent Switcher 2 EMI performance, making it ideal for powering automotive infotainment head units, ADAS cameras, radar sensors, and telematics modules. Its 2.5 µA quiescent current preserves battery life in always-on systems, while the HV temperature grade supports -40°C to +150°C operation. CISPR 25 Class 5 compliance is achievable with simple input filtering.
Recommandé
Industrial 48V to Point-of-Load Conversion
The LT8645SHV-2#PBF operates directly from 48V telecom and industrial bus rails without pre-regulation, stepping down to 3.3V, 5V, or 12V point-of-load voltages at 8A. Its 65V absolute maximum rating tolerates transient surges common on factory and telecom buses, and Silent Switcher 2 eliminates shielding that would otherwise bloat industrial PCB area. The exposed pad package provides robust thermal performance for continuous full-load operation.
Recommandé
Battery-Powered Portable Instruments
With 2.5 µA Burst Mode quiescent current, the LT8645SHV-2#PBF extends runtime in battery-powered test instruments, handheld scanners, and portable medical devices. It operates from as low as 3.4V input, allowing direct connection to single-cell Li-ion or multi-cell NiMH packs without boost pre-stage. The high efficiency at light loads minimizes self-discharge during standby.
Recommandé
Distributed POL in Server & Storage Systems
The LT8645SHV-2#PBF serves as a high-efficiency intermediate bus converter stepping 48V to 12V at 8A, feeding downstream point-of-load regulators in hyperscale servers and storage arrays. Silent Switcher 2 architecture meets Class A EMI limits without complex filtering, reducing BOM cost per rail. Paralleling multiple parts scales to 16A or higher with synchronized switching via the CLKOUT pin.
Recommandé
Noise-Sensitive RF & Analog Signal Chain Power
The LT8645SHV-2#PBF powers RF transceivers, ADCs, DACs, and precision analog front ends where switching noise would degrade signal integrity. Silent Switcher 2 minimizes both conducted and radiated emissions, often eliminating the need for post-LC filters. The wide VIN range supports direct connection to 24V industrial or rectified AC inputs.
Recommandé
General-Purpose High-Current Distributed Power
Beyond specialized applications, the LT8645SHV-2#PBF is a versatile building block for general 8A step-down needs including PoE devices, LED drivers, motor control auxiliaries, and HVAC controls. The 32-LQFN EP footprint integrates well with modern compact PCB layouts, while the 2.2 MHz maximum switching frequency enables small external inductors.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LT8645SHV-2#PBF — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | LT8645SEV#PBF | LT8645SJV-2#PBF | LT8646SEV#PBF | LT8646SIV#PBF |
|---|---|---|---|---|---|
| Package | 32-LQFN Exposed Pad | 32-LQFN Exposed Pad - same | 32-LQFN Exposed Pad - same | 32-LQFN Exposed Pad - same | 32-LQFN Exposed Pad - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Input Voltage Range | 3.4 V to 65 V | 3.4 V to 65 V | 3.4 V to 65 V | 3.4 V to 65 V | 3.4 V to 65 V |
| Output Current | 8 A | 8 A | 8 A | 10 A | 10 A |
| Output Voltage Range | 0.97 V to 65 V | 0.97 V to 65 V | 0.97 V to 65 V | 0.97 V to 65 V | 0.97 V to 65 V |
| Quiescent Current | 2.5 µA | 2.5 µA | 2.5 µA | 2.5 µA | 2.5 µA |
| Switching Frequency | Up to 2.2 MHz | Up to 2.2 MHz | Up to 2.2 MHz | Up to 2.2 MHz | Up to 2.2 MHz |
| Junction Temperature Range | -40 °C to +150 °C (HV) | -40 °C to +125 °C (EV) | -40 °C to +150 °C (JV) | -40 °C to +125 °C (EV) | -40 °C to +125 °C (IV) |
Principaux différenciateurs
- Highest VIN in class with 8A continuous output (vs LT8640IUDC-1#PBF)
- Integrated bypass capacitors reduce BOM (vs LT8606EDC#TRPBF)
- Silent Switcher 2 architecture for CISPR 25 compliance (vs Conventional buck regulators)
Notes de conception
Estimated: At VIN=24V, VOUT=5V, and full 8A load, the LT8645SHV-2 dissipates approximately (24-5)*8 = 152W, but typical synchronous buck efficiency at this operating point is ~93%, so actual dissipation is about 11W. The 32-LQFN EP package thermal resistance theta_JA is roughly 22 °C/W on a JEDEC 4-layer test board, giving a junction rise of ~242 °C above ambient at 11W - thermal shutdown may engage. Substantial copper pours (1-2 sq inch top layer) on PGND and the exposed pad are mandatory; at lower VIN-VOUT differentials (e.g., 12V to 5V) dissipation drops to ~3W which is far more manageable.
Place the input ceramic capacitors (typically 2x 4.7 µF X7R 100V) as close as possible to the VIN and PGND pins to minimize the high-frequency hot loop. The LT8645SHV-2 internal bypass capacitors reduce but do not eliminate the need for external high-frequency decoupling - add a 0.1 µF 100V X7R capacitor within 2 mm of each VIN/PGND pair. Use wide copper pours for the SW node to minimize parasitic inductance and radiated emissions.
Do not exceed 65V on VIN even transiently; the absolute maximum rating is 65V and load-dump transients on automotive 12V systems can reach 40V sustained plus ringing. Place a TVS diode (e.g., SMAJ58A) close to VIN for additional protection. The EN/UV pin must not be left floating - tie to VIN through a resistor divider for proper undervoltage lockout threshold setting. The BIAS pin should be tied to VOUT (when VOUT >= 3V) to maximize efficiency.
Per the Analog Devices datasheet layout guidelines, keep the feedback (FB) trace short and away from the SW node to avoid noise coupling. Use a Kelvin connection at the output capacitor for the VOUT sense pin. The exposed pad must be soldered to a ground plane with thermal vias (typically 5x5 array of 0.3mm vias) for proper heat extraction. Avoid routing signal traces under the inductor.
Informations de conformité
RoHS compliant per the #PBF suffix designation. AEC-Q100 status not explicitly stated in web data; the HV temperature grade supports automotive environments but formal AEC-Q100 qualification should be confirmed with Analog Devices for production automotive designs.
