LT8640SEV-2#PBF - 42V, 6A Synchronous Step-Down Silent Switcher | ADI
Référence : LT8640SEV-2#PBF ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $15.84 | $15,84 |
| 10 | $14.85 | $148,50 |
| 100 | $12.5 | $1 250,00 |
| 500 | $10.75 | $5 375,00 |
| 1 000 | $9.2 | $9 200,00 |
LT8640SEV-2#PBF Présentation
What is a Silent Switcher buck regulator? A synchronous buck converter is a switch-mode DC-DC topology that steps down a higher input voltage to a lower regulated output using a pair of MOSFET switches and an LC output filter; it replaces a traditional buck diode with a synchronous MOSFET to reduce conduction loss. The Silent Switcher 2 architecture further minimizes EMI by splitting the input hot loop into symmetrical parallel paths, enabling the LT8640SEV-2 to meet CISPR 25 / CISPR 32 Class 5 radiated and conducted EMI limits with minimal filtering, which is essential for noise-sensitive automotive and industrial designs.
Key specifications include a 30 ns minimum on-time that supports high step-down ratios even at 2 MHz switching frequency, 96% peak efficiency, 2.5 uA quiescent current in Burst Mode operation, and 200 kHz to 3 MHz programmable switching frequency. The device supports spread-spectrum frequency modulation, external clock synchronization, pulse-skipping, and forced continuous modes through the SYNC/MODE pin, and includes internal loop compensation to simplify PCB design. The 24-LQFN exposed pad provides low thermal resistance for sustained 6 A operation.
The peak current-mode control architecture with 30 ns minimum top switch on-time enables high VIN-to-low-VOUT conversion at high switching frequencies (e.g., 24 V to 1.0 V at 2 MHz). Internal MOSFETs are optimized for both high efficiency and thermal performance, supporting up to 6 A continuous load with no external heatsink required when VIN-VOUT differential is moderate.
Typical applications include automotive infotainment and ADAS power rails, industrial 24 V bus to point-of-load conversion, battery-powered systems (12 V / 24 V / 36 V Li-ion stacks), GPS / telematics modules, and low-EMI communications infrastructure. The 2.5 uA quiescent current also makes it suitable for always-on bias supplies.
Design trade-off: the -2 variant is specified for tighter EMI compliance but is otherwise equivalent to the LT8640SEV; the standard -1 (LT8640S/LT8640SA) and non-EMI -2 variants coexist on the same datasheet for design flexibility. Always place input ceramics directly at the VIN and PGND pins to maximize the benefit of Silent Switcher 2.
This page synthesizes distributor pricing, verified drop-in alternatives from the LT8640S / LT8643S-2 family, and practical design notes not duplicated in the manufacturer datasheet, providing an engineer-ready decision matrix for selecting the right synchronous buck for low-EMI applications.
Alternatives de remplacement direct pour LT8640SEV-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 LT8640SEV-2#PBF (même facteur de forme et même empreinte) — différant par Output Voltage Range, Architecture, MSL Level, Operating Junction Temperature, Package.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
LT8643SEV-2#PBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LT8640SEV#PBF
✅ Remplacement direct✓ En stock
$6.93 / unité
Voir la fiche technique →LT8640SHV-2#WPBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LT8640SIV#PBF
✅ Remplacement direct✓ En stock
$4.95 / unité
Voir la fiche technique →LT8642SIV#PBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LT8640SEV-2#PBF Valeurs maximales et caractéristiques électriques
| Topologie | Synchronous Step-Down (Buck) |
| Plage de tension d'entrée | 3.4 V to 42 V |
| Plage de tension de sortie | 0.97 V to 41.58 V (adjustable) |
| Courant de sortie maximal | 6 A |
| Switching Frequency Range | 200 kHz to 3 MHz |
| Minimum Switch On-Time | 30 ns |
| Peak Efficiency | 96% |
| Quiescent Current (Burst Mode) | 2.5 uA |
| Architecture | Silent Switcher 2 (ultra-low EMI) |
| Control Mode | Peak Current-Mode |
| Synchronization | External clock, SYNC/MODE pin (spread spectrum, pulse-skipping, forced continuous) |
| Boîtier | 24-LQFN-EP (4 mm x 6 mm) |
| Température de jonction en fonctionnement | -40C to +125C |
| Type de montage | Surface Mount |
| Niveau MSL | 3 |
| Statut RoHS | Compliant |
| EMI Compliance | CISPR 25 / CISPR 32 Class 5 (with minimal filtering) |
Configuration des broches de LT8640SEV-2#PBF
| Broche 1 | VIN — Input supply voltage |
| Broche 2 | VIN — Input supply voltage |
| Broche 3 | PGND — Power ground |
| Broche 4 | PGND — Power ground |
| Broche 5 | SW — Switch node (output to inductor) |
| Broche 6 | SW — Switch node (output to inductor) |
| Broche 7 | SW — Switch node (output to inductor) |
| Broche 8 | SW — Switch node (output to inductor) |
| Broche 9 | BOOST — Bootstrap capacitor for top gate drive |
| Broche 10 | BIAS — Internal LDO bias supply decoupling |
| Broche 11 | EN/UVLO — Enable / undervoltage lockout threshold |
| Broche 12 | RT — Timing resistor to program switching frequency |
| Broche 13 | SYNC/MODE — Sync input / mode selection (spread spectrum, pulse-skipping, forced continuous) |
| Broche 14 | FB — Voltage feedback for adjustable output |
| Broche 15 | PGND — Power ground (signal) |
| Broche 16 | PGND — Power ground |
| Broche 17 | PGND — Power ground |
| Broche 18 | PGND — Power ground |
| Broche 19 | VIN — Input supply voltage |
| Broche 20 | VIN — Input supply voltage |
| Broche 21 | NC — Not connected (per datasheet) |
| Broche 22 | NC — Not connected (per datasheet) |
| Broche 23 | NC — Not connected (per datasheet) |
| Broche 24 | NC — Not connected (per datasheet) |
| Broche EP | EP — Exposed thermal pad - solder to PGND copper pour for heatsinking |
Applications typiques
LT8640SEV-2#PBF convient pour 7 applications: Automotive Infotainment Power Rail, Industrial 24 V Bus Point-of-Load Conversion, Battery-Powered Portable Equipment, GPS and Telematics Modules, ADAS Sensor Power (Radar / Camera), Low-EMI Communications Infrastructure, Always-On Bias Supply for IoT Edge Nodes.
Automotive Infotainment Power Rail
The LT8640SEV-2#PBF powers 3.3 V / 5 V rails in head units, instrument clusters, and telematics modules from a 12 V / 24 V automotive battery bus. Its Silent Switcher 2 architecture and 30 ns minimum on-time let the part meet CISPR 25 Class 5 radiated/conducted EMI limits with only two small input ceramic capacitors, eliminating the bulky input pi-filters that conventional buck regulators require. Peak efficiency of 96% keeps dissipation under 2 W at typical infotainment loads (1-2 A), and the 2.5 uA Burst-Mode quiescent current preserves battery life during parked/standby states. The 42 V absolute input rating provides margin against 24 V truck-bus load-dump transients.
Recommandé
Industrial 24 V Bus Point-of-Load Conversion
The LT8640SEV-2#PBF steps down a 24 V industrial bus (18-32 V typical) to logic rails of 3.3 V, 5 V, or 12 V for PLCs, factory sensors, motor-control boards, and HMI panels. Its 42 V max input tolerates 24 V bus transients and 28 V MIL-STD surges, while the 3.4 V minimum VIN supports cold-start scenarios. Programmable switching frequency up to 3 MHz allows engineers to place the switching harmonics away from sensitive sensor bands; spread-spectrum mode further reduces EMI in dense multi-rail designs. The exposed thermal pad plus a 1 oz copper pour sustains full 6 A at 24 V-to-5 V conversion without external heatsinking.
Recommandé
Battery-Powered Portable Equipment
The LT8640SEV-2#PBF operates from 3.4 V to 42 V and consumes only 2.5 uA in Burst Mode, making it well-suited for battery stacks from 4S Li-ion (12-16.8 V) through 8S (28-33.6 V). Portable medical devices, test instruments, and field-deployed IoT gateways benefit from its high efficiency (>94% at 12 V-to-3.3 V) and low standby drain, which extends runtime directly. External clock synchronization allows multiple LT8640SEV-2 converters to operate 180 degrees out of phase, reducing input ripple and allowing smaller input capacitors in space-constrained portable designs.
Recommandé
GPS and Telematics Modules
The LT8640SEV-2#PBF provides clean 3.3 V / 1.8 V rails for GPS receivers, GNSS modules, and cellular telematics units from an automotive or asset-tracking battery. Silent Switcher 2 architecture prevents converter switching noise from desensitizing the GPS L1/L5 front end or causing phase error in GNSS positioning. The 30 ns minimum on-time supports 12 V-to-1.8 V conversion at 2 MHz with a small 1 uH inductor, reducing both BOM cost and PCB area. The 2.5 uA quiescent current is ideal for asset trackers that spend most of their life in sleep mode.
Recommandé
ADAS Sensor Power (Radar / Camera)
The LT8640SEV-2#PBF powers low-voltage rails for 77 GHz radar MMICs, forward-facing camera SoCs, and LiDAR sensor front ends from a 12 V or 24 V automotive supply. CISPR 25 Class 5 EMI compliance prevents the buck converter from raising the noise floor of sensitive analog front ends and high-speed ADCs. Synchronization to an external clock avoids beat-frequency interference with radar chirp or camera pixel clocks. Combined with the LT8640SHV-2#WPBF automotive-grade variant, the part supports AEC-Q100 designs for safety-critical ADAS functions.
Recommandé
Low-EMI Communications Infrastructure
The LT8640SEV-2#PBF powers base-station RF chains, small-cell radios, and PoE-powered network equipment where switching-noise-induced phase jitter and spurious emissions must be minimized. Silent Switcher 2 architecture with spread-spectrum modulation distributes noise energy across a wide band, simplifying system-level EMI compliance to EN 55032 Class B. The 200 kHz to 3 MHz programmable switching range allows the fundamental switching tone to be placed in guard bands between sensitive radio bands. Internal compensation eliminates external loop components, reducing PCB complexity in dense RF designs.
Recommandé
Always-On Bias Supply for IoT Edge Nodes
The LT8640SEV-2#PBF serves as the always-on bias supply in solar-powered IoT edge nodes, building-automation controllers, and remote sensor gateways. Burst Mode operation at 2.5 uA quiescent current keeps idle drain negligible while still providing fast load-step response for periodic sensor wake events. The wide 3.4 V to 42 V input range accepts direct connection to 12 V lead-acid, 24 V solar battery stacks, or rectified 24 VAC building-bus supplies without front-end regulation. Synchronization to a low-power 32.768 kHz-derived clock minimizes harmonics in the GNSS band.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LT8640SEV-2#PBF — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | LT8643SEV-2#PBF | LT8640SEV#PBF | LT8640SHV-2#WPBF | LT8640SIV#PBF | LT8642SIV#PBF |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 24-LQFN-EP (4x6 mm) | 24-LQFN-EP (4x6 mm) - same | 24-LQFN-EP (4x6 mm) - same | 24-LQFN-EP (4x6 mm) - same | 24-LQFN-EP (4x6 mm) - same | 24-LQFN-EP (4x6 mm) - same |
| 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 | 3.4 V to 42 V | 3.0 V to 42 V |
| Maximum Output Current | 6 A | 8.5 A (+42%) | 6 A | 6 A | 6 A | 10 A (+67%) |
| Silent Switcher Architecture | Silent Switcher 2 (ultra-low EMI) | Silent Switcher 2 (same) | Silent Switcher 1 (higher EMI) | Silent Switcher 2 (same) | Silent Switcher 1 (higher EMI) | Silent Switcher 1 (higher EMI) |
| AEC-Q100 Automotive Grade | No (industrial) | No (industrial) | No (industrial) | Yes (AEC-Q100) | No (industrial) | No (industrial) |
| Minimum Switch On-Time | 30 ns | 30 ns | 30 ns | 30 ns | 30 ns | 30 ns |
| Approx. 1ku List Price (USD) | $6.93 (LT8640S family starting price) | Higher (8.5 A upgrade) | Comparable | Higher (automotive grade) | Comparable | Higher (10 A upgrade) |
Principaux différenciateurs
- Silent Switcher 2 architecture delivers CISPR 25 Class 5 EMI with minimal filtering (vs LT8640SEV#PBF)
- Pin-compatible 8.5 A upgrade path without PCB redesign (vs LT8643SEV-2#PBF)
- AEC-Q100 automotive-qualified drop-in variant available (vs LT8640SHV-2#WPBF)
Notes de conception
Place two small input ceramic capacitors (e.g., 1 uF + 0.1 uF X7R) directly at the VIN and PGND pins as close as physically possible - this is critical for realizing the full Silent Switcher 2 EMI benefit. Use multiple vias from the LQFN exposed pad to a large PGND copper pour on inner/outer layers to keep junction temperature below 125C at full 6 A load. Estimated: at VIN=24V, VOUT=5V, IOUT=6A, power dissipation is approximately 1.8W, requiring ~1 sq.in. of 1-oz copper for safe operation.
Keep the SW node traces short and narrow to minimize radiated EMI from the high-dV/dt switching node. Place the output inductor away from noise-sensitive analog traces; if possible, shield the inductor with a grounded copper pour. Route the feedback (FB) trace away from the SW node and use a ground guard ring to prevent switching noise from coupling into the regulation loop. For multi-converter designs, synchronize all LT8640SEV-2 ICs 180 degrees out of phase via the SYNC/MODE pin to reduce input ripple.
Do not omit the BOOST capacitor (typically 0.1 uF) between BOOST and SW pins - without it, the top-side gate driver will fail and the converter will not start. Ensure RT resistor is within the 200 kHz to 3 MHz programming range; values outside this range can cause subharmonic instability. For automotive load-dump transients, verify the input TVS clamp limits transients below 42 V - the part's absolute maximum VIN is 42 V continuous with limited transient tolerance above. Do not exceed 6 A continuous without sufficient PCB thermal relief.
Informations de conformité
RoHS and lead-free compliant per Analog Devices product page (#PBF suffix). LT8640SEV-2#PBF is industrial grade; for AEC-Q100 automotive use choose LT8640SHV-2#WPBF. Halogen-free status not explicitly stated in distributor data.
