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Infineon Technologies IRF6645
- Part No.:
- IRF6645
- Manufacturer:
- Infineon Technologies
- Category:
- FETs, MOSFETs
- Package:
- DirectFET™ Isometric SJ
- Datasheet:
-
IRF6645.pdf
- Description:
- MOSFET N-CH 100V 5.7A DIRECTFET
- Quantity:
- Payment:
- Shipping:
Inventory:9,901
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Product details
Overview
IRF6645 from Infineon Technologies is an N-channel enhancement-mode power MOSFET in DirectFET® SJ package, optimized for primary-side switching and secondary-side synchronous rectification in isolated DC-DC converters. It delivers 28 mΩ RDS(on) at VGS = 10 V, 100 V VDSS, and 5.7 A continuous drain current at TA = 25°C, enabling high-efficiency operation in telecom (36–75 V input) and server power supplies.
For engineers reviewing the IRF6645 datasheet, IRF6645 pinout, IRF6645 application, or IRF6645 equivalent, key selection criteria include its ultra-low profile (0.7 mm), dual-sided cooling capability, 14 nC total gate charge, and 80% improved thermal resistance versus prior-generation packages - critical for compact, thermally constrained high-density power designs.
Technical Context
The IRF6645 employs HEXFET® silicon with trench-gate structure to minimize conduction and switching losses. Its DirectFET SJ outline integrates source and drain terminals on opposite sides of a copper substrate, enabling simultaneous top-side (drain) and bottom-side (source) thermal interface to heatsinks or PCB planes.
Designed for hard-switched and resonant topologies, it features high dV/dt immunity (≥50 V/ns), low reverse recovery charge (Qrr = 40–60 nC), and robust unclamped inductive switching capability (EAS = 100 mJ at IAS = 3.4 A), supporting reliable operation in bridge-leg and synchronous rectifier configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDSS | 100 V - supports 75 V universal telecom input with 33% voltage margin for transients |
| RDS(on) | 28 mΩ @ VGS = 10 V - reduces conduction loss to ≤160 mW at 5.7 A, easing thermal design |
| Qg | 14 nC - enables fast turn-on with low gate drive power, suitable for 500 kHz+ switching |
| Qgd | 4.8 nC - limits Miller-induced shoot-through risk in half-bridge layouts |
| RθJC | 3.0 °C/W - allows >20 W power dissipation with modest case-to-heatsink thermal interface |
| ID (TA = 25°C) | 5.7 A - sustains full-load current in 30–60 W isolated DC-DC stages without derating |
| VGS(th) | 4.0 V typical - ensures clean turn-on with standard 5 V or 3.3 V logic-level gate drivers |
Pinout & Package
IRF6645 uses the DirectFET® SJ (Small Size Can, J-Designation) package - a copper-can, double-sided surface-mount construction with drain on top, source on bottom, and gate on the side. Footprint matches Micro8 layout, height is 0.7 mm, and thermal pad is soldered directly to PCB ground plane or heatsink.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Top Metal Surface | Drain (D) | Primary high-side switching node; serves as top-side thermal path to heatsink or chassis |
| Bottom Metal Pad | Source (S) | Low-side return path; provides bottom-side thermal conduction to PCB copper pour or heatsink |
| Side Tab (marked "G") | Gate (G) | Control terminal; requires <10 Ω gate resistor to suppress oscillation during fast switching |
Key Features
| Feature | Design Value |
|---|---|
| Dual-sided cooling | Enables simultaneous top (drain) and bottom (source) thermal interface, reducing RθJA by 80% vs. SO-8 |
| Ultra-low profile (0.7 mm) | Permits integration into space-constrained modules such as quarter-brick DC-DC converters |
| High dV/dt immunity | Withstands ≥50 V/ns voltage transients without spurious turn-on in noisy bridge environments |
| Optimized for synchronous rectification | Low Qrr (40–60 nC) and fast trr (31–47 ns) minimize body diode conduction loss in secondary-side FETs |
| RoHS-compliant & halogen-free | Qualified for lead-free reflow up to 260°C, compatible with IPC-J-STD-020 moisture sensitivity Level 1 |
Applications
| Telecom AC/DC Front-End | Isolated DC-DC Primary Switch |
|---|---|
Use Scenario: 48 V telecom rectifier with active PFC and LLC resonant stage. IC Role / Device Role / Timing Role: Primary-side high-side switch in asymmetric half-bridge topology operating at 200–500 kHz. Use Value: 28 mΩ RDS(on) and 14 nC Qg reduce combined conduction + switching loss to <1.2 W, enabling >95% efficiency at full load. | Use Scenario: 12 V output, 60 W isolated forward converter in network equipment. IC Role / Device Role / Timing Role: Main switch in primary-side active clamp forward topology. Use Value: Dual-sided cooling maintains TJ < 105°C under 60 W continuous load, eliminating need for forced air. |
| Server VRM Synchronous Rectifier | Industrial Isolated Auxiliary Supply |
Use Scenario: Secondary-side synchronous rectification in 12 V → 1.2 V multiphase VRM. IC Role / Device Role / Timing Role: Low-side rectifying FET driven by adaptive gate controller. Use Value: 40–60 nC Qrr and 31–47 ns trr cut body diode conduction loss by 65% vs. Schottky alternatives. | Use Scenario: 24 V input, 5 V/2 A auxiliary supply for PLC I/O modules. IC Role / Device Role / Timing Role: Primary switch in flyback converter with 100 V breakdown margin. Use Value: 100 V VDSS and -40°C to +150°C TJ rating ensure reliability across industrial ambient extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar N-channel power MOSFET applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IRF6662 | Higher VDSS (150 V), higher RDS(on) (42 mΩ), same DirectFET SJ package | Better suited for 110 VAC input or 48 V battery systems with higher surge requirements | Select when system transient voltage exceeds 100 V but thermal budget allows higher conduction loss |
| SiR626DP | Same VDSS (100 V), lower RDS(on) (23 mΩ), TSDFN package (0.95 mm height), different footprint | Requires PCB redesign; offers better RDS(on) but no dual-sided cooling | Choose only if board space permits new layout and top-side cooling is not required |
Compared with IRF6645, IRF6662 trades conduction efficiency for higher voltage ruggedness, while SiR626DP improves on-resistance but sacrifices the thermal advantage of dual-sided cooling - making IRF6645 optimal where both 100 V rating and ultra-low thermal resistance are simultaneously required.
Availability
IRF6645 is available at Aetrix Electronics and suitable for telecom rectifiers, isolated DC-DC converters, server VRMs, and industrial auxiliary power supplies requiring stable component supply and long-term production continuity.
Supply support for IRF6645 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs and discrete devices, with global manufacturing and quality certification to ISO/TS 16949 and IATF 16949.
The IRF6645 belongs to Infineon's DirectFET® power MOSFET product line, engineered specifically for high-frequency, high-efficiency isolated power conversion where thermal density and switching loss are critical constraints.
FAQ
What is the maximum continuous drain current for IRF6645 at 70°C ambient?
The IRF6645 supports 4 A continuous drain current at TA = 70°C with standard PCB mounting (1 in² Cu board). This rating assumes natural convection cooling and accounts for thermal derating above 25°C ambient, per the absolute maximum ratings table in the official datasheet.
Can IRF6645 be used in synchronous rectification without external gate driving circuitry?
No - IRF6645 requires active gate control. Its 4.0 V typical VGS(th) and 14 nC Qg necessitate a dedicated gate driver (e.g., IR1167 or LM5113) to achieve zero-voltage switching alignment and prevent cross-conduction in synchronous rectifier applications.
Does IRF6645 have avalanche energy rating, and what is its value?
Yes - IRF6645 is rated for 100 mJ single-pulse avalanche energy (EAS) at IAS = 3.4 A, measured under standardized unclamped inductive test conditions (L = 5.0 mH, RG = 25 Ω, starting TJ = 25°C). This supports robustness against inductive switching faults in hard-switched topologies.
Is the DirectFET SJ package compatible with standard reflow soldering processes?
Yes - the IRF6645 DirectFET SJ package is qualified for lead-free reflow up to 260°C peak temperature and complies with IPC-J-STD-020 moisture sensitivity Level 1. Successful assembly requires adherence to Application Note AN-1035 for stencil design, substrate layout, and vapor-phase or convection profile settings.
IRF6645 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- HEXFET®
- Package/Case:
- DirectFET™ Isometric SJ
- Packaging:
- Tube
- Product Status:
- Obsolete
- FET Type:
- N-Channel
- Technology:
- MOSFET (Metal Oxide)
- Drain to Source Voltage (Vdss):
- 100 V
- Current - Continuous Drain (Id) @ 25°C:
- 5.7A (Ta), 25A (Tc)
- Drive Voltage (Max Rds On, Min Rds On):
- 10V
- Rds On (Max) @ Id, Vgs:
- 35mOhm @ 5.7A, 10V
- Vgs(th) (Max) @ Id:
- 4.9V @ 50µA
- Gate Charge (Qg) (Max) @ Vgs:
- 20 nC @ 10 V
- Vgs (Max):
- ±20V
- Input Capacitance (Ciss) (Max) @ Vds:
- 890 pF @ 25 V
- FET Feature:
- -
- Power Dissipation (Max):
- 3W (Ta), 42W (Tc)
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DIRECTFET™ SJ
IRF6645 FAQ
1.How can I place an order for IRF6645 through Aetrix?
Please submit a Request for Quotation (RFQ) for IRF6645 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for IRF6645 reliable?
The price and inventory of IRF6645 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRF6645 is usually 5 days.
3.What payment methods are accepted for IRF6645?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRF6645 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IRF6645?
IRF6645 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IRF6645 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for IRF6645?
For technical support, including IRF6645 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRF6645 requirements.
6.How does Aetrix verify that IRF6645 is sourced from the original manufacturer or authorized distributors?
All IRF6645 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that IRF6645 meets industry standards.
7.What is the process for return or replacement of IRF6645?
All IRF6645 units undergo pre-shipment inspection (PSI). If there is an issue with IRF6645, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The IRF6645 part is unused and in its original packaging.
Return procedure for IRF6645:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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