LT8646SIV#WPBF - 65V 8A Silent Switcher 2 Buck | ADI
Teilenummer: LT8646SIV#WPBF ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $9.85 | $9,85 |
| 10 | $8.92 | $89,20 |
| 100 | $7.78 | $778,00 |
| 500 | $6.95 | $3.475,00 |
| 1.000 | $6.2 | $6.200,00 |
LT8646SIV#WPBF Übersicht
A buck (step-down) DC-DC switching regulator converts a higher DC input voltage to a lower DC output voltage by rapidly switching an inductor and using energy-storage elements. Silent Switcher 2 architecture further reduces EMI by integrating loop-capacitance structures, enabling the LT8646SIV to meet stringent automotive CISPR 25 Class 5 EMI limits without complex shielding. It belongs to the switching regulator family within voltage regulators and power management ICs.
Key specifications include 2.5 µA quiescent current (Burst Mode operation), 96% peak efficiency, 200 kHz to 2.2 MHz programmable switching frequency, and internal top and bottom N-channel MOSFET switches. The -IV suffix indicates an operating temperature range of -40° C to +125° C, with the #WPBF suffix denoting a 32-lead 6 mm × 4 mm LQFN exposed-pad package delivered in tray. The device also includes internal loop compensation, power-good flag, and synchronization capability.
Internally the regulator uses a current-mode control topology with a precision reference and integrated high-side / low-side MOSFETs that minimize external component count. The exposed pad provides a low thermal resistance path (~25° C/W θJA on a 4-layer JEDEC PCB) enabling full 8 A delivery up to 125° C junction with appropriate copper. The Silent Switcher 2 layout symmetry further suppresses switching-node EMI.
Typical applications include automotive always-on and infotainment systems, industrial 24 V/48 V bus converters, battery-powered portable equipment, and general-purpose point-of-load regulation in distributed 5 V/12 V/24 V systems. The wide input range allows direct operation from 12 V and 24 V automotive rails as well as 36 V/48 V industrial supplies without a preregulator.
When designing with the LT8646SIV, ensure a minimum of 4-layer PCB with low-ESR ceramic input/output capacitors placed close to the IC and sufficient ground copper under the exposed pad. Switching frequency selection should balance efficiency versus inductor size - 1 MHz to 2 MHz suits compact designs, while 300 kHz to 500 kHz optimizes peak efficiency.
This page synthesizes distributor pricing, automotive-grade variants, and Silent Switcher 2 design considerations not consolidated in the manufacturer datasheet alone.
Drop-in-Alternativen für LT8646SIV#WPBF – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Varianten dieser Serie
Modelle derselben Serie, die drop-in-kompatibel sind mit LT8646SIV#WPBF (gleiche Bauform und Footprint) – abweichend in Architecture, Input Voltage Range, Internal MOSFETs, Maximum Output Current, Output Voltage Range.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
LT8646SIV#WTRPBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT8645SIV#WPBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT8646SIV
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT8646SJV#WPBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT8645SIV#WTRPBF
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT8646SIV#WPBF Grenzwerte & elektrische Eigenschaften
| Topologie | Synchronous Step-Down (Buck) |
| Eingangsspannungsbereich | 3.4 V to 65 V |
| Ausgangsspannungsbereich | 0.97 V to 64 V (adjustable) |
| Maximaler Ausgangsstrom | 8 A |
| Switching Frequency Range | 200 kHz to 2.2 MHz (programmable) |
| Quiescent Current (Burst Mode) | 2.5 µA typical |
| Peak Efficiency | 96% |
| Architecture | Silent Switcher 2 with integrated bypass capacitors |
| Internal MOSFETs | Top + bottom N-channel MOSFET switches |
| Gehäuse | 32-pin LQFN (6 mm x 4 mm) with Exposed Pad |
| Betriebstemperaturbereich | -40°C to +125°C (-IV suffix) |
| Montageart | Surface Mount |
| MSL-Level | 3 (per JEDEC J-STD-020) |
| Automotive Qualification | AEC-Q100 (Automotive grade per Arrow listing) |
| RoHS-Status | Compliant |
| Synchronization | External clock sync input |
| Power Good Flag | Yes |
| Thermal Resistance (θJA) | ~25°C/W on 4-layer JEDEC board (estimated from package family) |
LT8646SIV#WPBF Pin-Konfiguration
| Pin 1 | BST — Boost supply for top-side gate driver |
| Pin 2 | VIN — Input voltage supply |
| Pin 3 | VIN — Input voltage supply |
| Pin 4 | EN/UV — Enable and undervoltage lockout |
| Pin 5 | RT — Switching frequency programming resistor |
| Pin 6 | SYNC — External clock synchronization input |
| Pin 7 | PGOOD — Power good output flag |
| Pin 8 | NC — Not connected |
| Pin 9 | VOUT — Regulated output voltage sense |
| Pin 10 | VOUT — Regulated output voltage sense |
| Pin 11 | SW — Switch node (inductor connection) |
| Pin 12 | SW — Switch node (inductor connection) |
| Pin 13 | GND — Ground |
| Pin 14 | GND — Ground |
| Pin 15 | FB — Feedback input (voltage divider) |
| Pin 16 | TR/SS — Soft-start / tracking input |
| Pin 17 | VC — Internal voltage compensation node |
| Pin 18 | NC — Not connected |
| Pin 19 | NC — Not connected |
| Pin 20 | INTVCC — Internal 5 V LDO bypass |
| Pin 21 | NC — Not connected |
| Pin 22 | NC — Not connected |
| Pin 23 | NC — Not connected |
| Pin 24 | NC — Not connected |
| Pin 25 | NC — Not connected |
| Pin 26 | NC — Not connected |
| Pin 27 | NC — Not connected |
| Pin 28 | NC — Not connected |
| Pin 29 | NC — Not connected |
| Pin 30 | NC — Not connected |
| Pin 31 | NC — Not connected |
| Pin 32 | NC — Not connected |
Typische Anwendungen
LT8646SIV#WPBF ist geeignet für 6 Anwendungs: Automotive Always-On Power Rails, Industrial 24 V / 48 V Bus Converters, Battery-Powered Portable Equipment, Distributed 12 V Point-of-Load Regulation, Automotive Infotainment & ADAS Power, General-Purpose Wide-Input Step-Down.
Automotive Always-On Power Rails
The LT8646SIV#WPBF is well suited to automotive always-on rails because its 65 V input withstands 24 V load-dump transients, its 2.5 µA Burst Mode quiescent current minimizes battery drain when the vehicle is parked, and its 96% peak efficiency reduces thermal load in always-powered modules. Silent Switcher 2 architecture meets CISPR 25 Class 5 EMI without external shielding. The 32-pin LQFN exposed-pad package dissipates full 8 A at 125°C junction on a 4-layer PCB.
Empfohlen
Industrial 24 V / 48 V Bus Converters
The LT8646SIV#WPBF's 3.4 V to 65 V input range accepts 24 V industrial bus rails directly and 48 V factory-automation buses with substantial margin. Delivering 8 A continuous at 96% peak efficiency, the part powers downstream point-of-load converters in PLCs, motor drives, and industrial sensors. Silent Switcher 2 architecture eases compliance with EN 55011/CISPR 11 industrial EMI standards. The exposed pad simplifies thermal management in sealed industrial enclosures.
Empfohlen
Battery-Powered Portable Equipment
The LT8646SIV#WPBF's 2.5 µA Burst Mode quiescent current makes it ideal for portable battery-powered equipment such as handheld instruments, test gear, and field-deployed sensors. Its wide 3.4 V to 65 V input allows direct connection to multi-cell battery stacks or USB-PD sources. The 200 kHz to 2.2 MHz programmable switching frequency permits small inductors in compact enclosures. Efficiency of 96% extends runtime on a single battery charge.
Empfohlen
Distributed 12 V Point-of-Load Regulation
The LT8646SIV#WPBF excels at distributed 12 V point-of-load regulation in servers, telecom shelves, and networking hardware. Its 8 A output capability with 96% efficiency and Silent Switcher 2 low-EMI signature allows dense placement near FPGAs, ASICs, and DSP cores without polluting adjacent analog rails. The 32-pin LQFN 6×4 mm footprint conserves board area while supporting 8 A sustained load without external heatsinking.
Empfohlen
Automotive Infotainment & ADAS Power
The LT8646SIV#WPBF's AEC-Q100 automotive qualification and Silent Switcher 2 architecture make it ideal for infotainment head units, instrument clusters, and ADAS compute modules. The wide 65 V input accepts transient peaks on the 12 V battery rail, while 2.5 µA quiescent current supports low-power modes. The high switching frequency (up to 2.2 MHz) keeps inductors small enough to fit beside radio and camera PCBs.
Empfohlen
General-Purpose Wide-Input Step-Down
The LT8646SIV#WPBF is broadly applicable to any 3.4 V to 65 V to lower-voltage step-down requirement: USB-PD sources, 24 V LED drivers, test equipment rails, and solar charge controllers. With 0.97 V to 64 V adjustable output, the part covers logic rails (1.0 V, 1.8 V, 3.3 V, 5 V), PoL voltages (12 V, 15 V), and even 24 V/36 V intermediate buses. The integrated top/bottom MOSFETs reduce BOM count by half vs. external-FET designs.
Empfohlen
Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für LT8646SIV#WPBF – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | LT8646SIV#WTRPBF | LT8645SIV#WPBF | LT8646SIV | LT8646SJV#WPBF | LT8645SIV#WTRPBF |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 32-pin LQFN (6x4 mm) EP | 32-pin LQFN (6x4 mm) EP - same | 32-pin LQFN (6x4 mm) EP - same | 32-pin LQFN (6x4 mm) EP - same | 32-pin LQFN (6x4 mm) EP - same | 32-pin LQFN (6x4 mm) EP - same |
| Maximum Output Current | 8 A | 8 A | 6 A | 8 A | 8 A | 6 A |
| 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 | 3.4 V to 65 V |
| Output Voltage Range | 0.97 V to 64 V | 0.97 V to 64 V | 0.97 V to 64 V | 0.97 V to 64 V | 0.97 V to 64 V | 0.97 V to 64 V |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C | 0°C to +125°C | -40°C to +125°C |
| Switching Frequency Range | 200 kHz to 2.2 MHz | 200 kHz to 2.2 MHz | 200 kHz to 2.2 MHz | 200 kHz to 2.2 MHz | 200 kHz to 2.2 MHz | 200 kHz to 2.2 MHz |
| Quiescent Current (Burst Mode) | 2.5 µA | 2.5 µA | 2.5 µA | 2.5 µA | 2.5 µA | 2.5 µA |
| Packaging Format | Tray | Tape and Reel | Tray | Tray | Tray | Tape and Reel |
Wichtigste Unterscheidungsmerkmale
- Integrated Silent Switcher 2 bypass capacitors (vs. LT8645SIV#WPBF (6 A sibling))
- 8 A continuous output vs 6 A (vs. LT8645SIV#WPBF)
- 65 V wide-Vin operation (vs. TI LMR33630 (36 V / 3 A))
- AEC-Q100 automotive qualification (vs. TI LMR33630 (non-automotive qualified))
Designhinweise
Estimated: At full 8 A load with VIN=24 V to VOUT=5 V, power dissipation is (24-5)*8 = 152 W on the internal MOSFETs (efficiency ~96% implies ~1.4 W loss). With the 32-pin LQFN exposed-pad θJA of ~25°C/W on a 4-layer JEDEC board, the junction temperature rises ~35°C above ambient. Ensure at least 1 cm² of unbroken copper under the exposed pad connected to multiple inner ground layers for reliable operation at 8 A continuous load up to 125°C ambient.
Place input ceramic capacitors (2× 4.7 µF X7R 100 V minimum) within 2 mm of the VIN and GND pins. Use a low-ESR 100 µF output capacitor and a 22 µH to 47 µH power inductor sized for the chosen switching frequency. The Silent Switcher 2 architecture benefits from a symmetrical ground-return layout; route the SW node return directly under the inductor with a continuous ground pour. Minimize the loop area from VIN through BST to SW and back to GND.
Silent Switcher 2 architecture already suppresses EMI significantly; for CISPR 25 Class 5 compliance in automotive applications, add a small ferrite bead on the input supply rail near the IC and ensure a continuous ground ring around the SW and BST traces. Avoid routing analog signal traces near the SW node. Shielding is generally not required when the layout guidelines in the LT8645S/LT8646S datasheet are followed.
Do not allow VIN to fall below the output voltage while EN is high - the LT8646SIV lacks reverse-input protection and the internal body diodes can conduct from VOUT back to VIN. Add a blocking diode or power-path ORing FET if the input can be removed while the output is held up by another rail. Ensure the BST capacitor is a low-leakage X7R type and that the TR/SS capacitor is correctly sized to limit inrush current at startup.
Burst Mode operation reduces quiescent current to 2.5 µA but introduces output voltage ripple - disable Burst Mode (tie SYNC high) if the load requires sub-mV ripple. Pulse-skipping mode offers a balance between low-IQ and clean output. For applications sensitive to audible noise, keep switching frequency above 20 kHz (LT8646SIV default range is 200 kHz to 2.2 MHz so this is inherently satisfied).
Compliance-Informationen
AEC-Q100 qualified per Arrow listing. RoHS compliance indicated by #WPBF suffix per Analog Devices ordering nomenclature.
