AUIRF7640S2TR - 60V 21A DirectFET MOSFET for Class D | Infineon
MPN: AUIRF7640S2TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.48 | $148.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
AUIRF7640S2TR Overview
A DirectFET MOSFET is a chip-scale surface-mount power package in which the silicon die is mounted on a metallic can that forms both the drain contact and a low-resistance thermal path to the PCB. Unlike a standard SO-8 or DPAK, DirectFET places the source and gate on the top side and the drain on the bottom, providing an extremely low package resistance and superior thermal performance for the same footprint. The DirectFET SB case variant is widely used in audio amplifier output stages where both low RDS(on) and clean thermal management are required.
Key features include a logic-level compatible gate drive, low total gate charge (Qg = 7.3 nC typical) that minimizes driver losses, and an automotive-grade qualification flow targeting AEC-Q101 reliability. The part is rated for avalanche operation and is intended for high-frequency PWM switching in the 250 kHz to 500 kHz range typical of Class D amplifiers. The DirectFET SB land pattern is electrically and thermally compatible with industry-standard layouts, simplifying PCB design and enabling vapor-phase, infrared, or conventional reflow soldering.
Typical applications include automotive Class D audio amplifiers (4 Ω and 8 Ω loads), high-current DC-DC synchronous rectifiers, motor drive half-bridges, and OR-ing FETs in redundant power systems. The combination of 60 V rating and 21 A continuous drain current makes it suitable for 12 V and 24 V automotive bus rails where load-dump transients must be tolerated.
When designing with this part, ensure that the PCB copper area under the DirectFET can is sized to keep junction temperature below 150 °C at worst-case load. The gate drive should swing at least 10 V for full RDS(on) optimization, although the part will turn on at 4.5 V. Always consult the manufacturer datasheet for SOA curves and thermal derating under pulsed audio loads.
Drop-in alternatives for AUIRF7640S2TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AUIRF7640S2TR (same form factor and footprint) — differing in Automotive Qualification, Package, Technology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AUIRF7640S2TR1
✅ Drop-In📋 Reference alternative (not in catalog)
AUIRF7640S2
✅ Drop-In📋 Reference alternative (not in catalog)
AUIRF7769L2TR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.78 / Unit
View Datasheet →IRF6645TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRF7240TRPBF
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
AUIRF7640S2TR Maximum Ratings & Electrical Characteristics
| FET Type | N-Channel |
| Drain-Source Voltage (VDS) | 60 V |
| Continuous Drain Current (ID) @ TA=25C | 5.8 A |
| Continuous Drain Current (ID) @ TC=25C | 21 A |
| Power Dissipation (PD) @ TA=25C | 2.4 W |
| Power Dissipation (PD) @ TC=25C | 30 W |
| On-Resistance RDS(on) | 36 mΩ |
| Total Gate Charge (Qg) | 7.3 nC |
| Package | DirectFET SB (Surface Mount) |
| Mounting Type | Surface Mount |
| Technology | HEXFET Power MOSFET (Automotive Grade) |
| Automotive Qualification | AEC-Q101 (Automotive Grade per datasheet) |
| Primary Application | Automotive Class D audio amplifier output stage |
AUIRF7640S2TR directfet sb (surface mount) Pin Configuration Guide
Pin configuration for AUIRF7640S2TR (directfet sb (surface mount) package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for AUIRF7640S2TR.
Refer to the datasheet for full pin configuration.
Safe Operating Area - DC
Typical Applications
AUIRF7640S2TR is suitable for 6 applications: Automotive Class D Audio Amplifier Output Stage, Automotive 12V/24V Synchronous Buck Converter, Automotive DC Motor Drive Half-Bridge, Automotive OR-ing / Power Muxing FET, Industrial High-Frequency Switching Power Supply, Automotive LED Driver Output Stage.
Automotive Class D Audio Amplifier Output Stage
The AUIRF7640S2TR is specifically designed for automotive Class D audio amplifier output stages switching at 250 kHz to 500 kHz PWM frequencies into 4 Ω and 8 Ω speaker loads. Per the Infineon datasheet, its 36 mΩ RDS(on) at VGS = 10 V minimizes conduction loss, while the 7.3 nC total gate charge keeps driver switching losses low. The DirectFET SB package's low package resistance and excellent thermal path to PCB copper enable continuous 21 A output current at 25 °C case temperature without external heatsinking. AEC-Q101 automotive qualification ensures the part survives underhood thermal cycling and load-dump transients typical of 12 V automotive electrical systems.
Recommended
Automotive 12V/24V Synchronous Buck Converter
The AUIRF7640S2TR functions as a low-side synchronous rectifier in 12 V and 24 V automotive DC-DC converters, where its 36 mΩ RDS(on) and 60 V VDS rating provide headroom for transient events. According to the Infineon datasheet, the part's DirectFET SB package occupies less board area than DPAK while offering superior thermal coupling. The 7.3 nC Qg simplifies gate-drive design in 200 kHz to 500 kHz buck topologies commonly used for automotive infotainment and ADAS power rails.
Recommended
Automotive DC Motor Drive Half-Bridge
The AUIRF7640S2TR is well-suited as a high-side or low-side switch in automotive brushed DC motor half-bridges for pumps, fans, and small actuators. The Infineon datasheet specifies 21 A continuous ID at TC and avalanche ruggedness, enabling direct drive of inductive loads without additional protection. The DirectFET SB package handles the high di/dt and dv/dt of PWM motor control at 20 kHz to 50 kHz without ringing issues common to wire-leaded packages.
Recommended
Automotive OR-ing / Power Muxing FET
The AUIRF7640S2TR serves as an OR-ing FET in redundant automotive power systems such as dual-battery setups and eCall backup supplies. According to the Infineon datasheet, the low 36 mΩ RDS(on) minimizes voltage drop and power dissipation in continuous-carry applications, while the 60 V VDS rating tolerates jump-start and load-dump transients. The DirectFET SB package's low thermal impedance keeps junction temperature low without external heatsinking.
Recommended
Industrial High-Frequency Switching Power Supply
The AUIRF7640S2TR is used in industrial switch-mode power supplies where 60 V VDS, 21 A continuous ID, and DirectFET SB thermal performance are required. Per the Infineon datasheet, the part supports hard-switched topologies up to 500 kHz and resonant topologies beyond 1 MHz, taking advantage of low Qrr and low Qg. Automotive-grade reliability provides extended MTBF in 24/7 industrial installations.
Recommended
Automotive LED Driver Output Stage
The AUIRF7640S2TR can be used as a constant-current regulator or PWM switch in high-brightness automotive LED headlight and daytime running light applications. The Infineon datasheet specifies that the part's 36 mΩ RDS(on) and DirectFET SB thermal performance handle the 2 A to 5 A continuous currents typical of automotive LED strings. AEC-Q101 qualification and the -40 °C to +150 °C operating range match underhood and headlamp module environments.
Recommended
Recommended Products Summary
Engineering reference data for AUIRF7640S2TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AUIRF7640S2TR1 | AUIRF7640S2 | AUIRF7769L2TR | IRF6645TRPBF | IRF7240TRPBF |
|---|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | DirectFET SB | DirectFET SB - same | DirectFET SB - same | DirectFET L2 - same family, different case | DirectFET SB - same | DirectFET MZ - same family, different case |
| Drain-Source Voltage (VDS) | 60 V | 60 V | 60 V | 100 V | 100 V | 40 V |
| Continuous Drain Current (ID @ TC) | 21 A | 21 A | 21 A | 10 A | 19 A | 20 A |
| On-Resistance RDS(on) | 36 mΩ | 36 mΩ | 36 mΩ | 12 mΩ | 40 mΩ | 50 mΩ |
| Total Gate Charge (Qg) | 7.3 nC | 7.3 nC | 7.3 nC | 20 nC | 8.0 nC | 15 nC |
| Automotive Qualification | AEC-Q101 | AEC-Q101 | AEC-Q101 | AEC-Q101 | Industrial grade (non-auto) | Industrial grade (non-auto) |
| Primary Application | Class D audio amplifier | Class D audio amplifier | Class D audio amplifier | High-frequency DC-DC | DC-DC synchronous rectification | Low-voltage DC-DC sync rect |
Key Differentiators
- Automotive-grade qualification on a DirectFET-class part (vs IRF6645TRPBF)
- Lower RDS(on) than IRF6645 in same package (vs IRF6645TRPBF)
- Right voltage rating for 12V/24V automotive bus (vs IRF7240TRPBF)
Design Notes
Estimated: at ID = 10 A continuous and RDS(on) = 36 mΩ, conduction loss is approximately 3.6 W. Using a typical DirectFET SB junction-to-ambient thermal resistance of 50 C/W on a 1 oz 2 square-inch copper pour, junction temperature rises 180 °C above ambient. For continuous Class D audio operation, increase PCB copper area to at least 3-4 square inches or use multiple thermal vias to an internal copper plane to keep Tj below 150 °C. Always consult the manufacturer datasheet SOA curves for your specific pulse profile.
DirectFET SB layout requires that the drain copper pad cover the entire footprint of the metal can, with multiple thermal vias stitching to the opposite copper plane. Gate and source pads are on the top side of the package. Place the gate driver within 5 mm of the gate pad to minimize parasitic inductance; for switching above 100 kHz, add a 10 Ω gate-source resistor to prevent ringing.
Do not exceed VGS = ±20 V absolute maximum, even though the part is rated to handle avalanche. For Class D audio half-bridges, ensure the gate-source voltage of the high-side FET does not exceed ratings during the bootstrap charge phase - use a bootstrap capacitor with at least 100 nF and verify the high-side supply voltage under worst-case audio load.
Compliance Information
AEC-Q101 qualified (MOSFET automotive standard, distinct from AEC-Q100 which is for ICs). RoHS and lead-free per Infineon product page.
