IRF4905STRLPBF - 55V P-Channel HEXFET MOSFET, 74A, D2PAK | Infineon
MPN: IRF4905STRLPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.35 | $135.00 |
| 500 | $1.12 | $560.00 |
| 1,000 | $0.95 | $950.00 |
Drop-in alternatives for IRF4905STRLPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
IRF4905STRLPBF-Q1
✅ Drop-In📋 Reference alternative (not in catalog)
IRF4905STRRPBF
✅ Drop-In✓ In Stock
$0.94 / Unit
View Datasheet →IRF4905SPBF
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →IRF4905STRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRF4905STRLPBF Maximum Ratings & Electrical Characteristics
| FET Type | P-Channel |
| Drain-Source Voltage (VDS) | -55 V |
| Continuous Drain Current (ID) at Tc=25C | -74 A |
| Pulsed Drain Current (IDM) | -260 A |
| Gate-Source Voltage (VGS) max | ±20 V |
| On-Resistance RDS(on) at VGS=-10V | 20 mOhm |
| Total Gate Charge (Qg) | 120 nC |
| Power Dissipation (PD) at Tc=25C | 170 W |
| Operating Temperature Range | -55C to +175C |
| Package | D2PAK (TO-263) |
| Mounting Type | Surface Mount |
| Technology | HEXFET (Planar) |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
IRF4905STRLPBF Pin Configuration
| Pin 1 | Gate — MOSFET gate control input (drive to source voltage minus 10V for full enhancement) |
| Pin 2 | Drain — MOSFET drain (electrically tied to the metal tab on the bottom of the package) |
| Pin 3 | Source — MOSFET source (main current terminal) |
| Pin TAB | Drain — Metal tab on bottom of package, electrically tied to drain pin 2 - serves as thermal dissipation pad and must be soldered to PCB copper pour |
Safe Operating Area - IRF4905STRLPBF
Typical Applications
IRF4905STRLPBF is suitable for 6 applications: Reverse-Battery Protection, DC Motor Drive High-Side Switch, Synchronous Rectifier in DC-DC Converters, Hot-Swap / Inrush Limiting Circuit, Battery Management / Power ORing, Industrial Load Switch / Power Distribution.
Reverse-Battery Protection
The IRF4905STRLPBF is widely used as the high-side P-channel switch in automotive and industrial reverse-battery protection circuits. With -55V VDS and -74A continuous current, it can interrupt fault currents from a mis-wired 24V truck battery while the 20 mOhm RDS(on) keeps conduction loss below 4W at 14A. Source is tied to the load, drain to the battery negative rail, and gate is pulled to ground through a Zener-clamped resistor network. The low RDS(on) avoids the need for an external bypass relay in most 12V passenger-vehicle applications.
Recommended
DC Motor Drive High-Side Switch
In brushed DC motor drive circuits, the IRF4905STRLPBF serves as the high-side P-channel switch that turns motor power on and off under PWM control. Its -74A continuous rating handles stall currents of small DC gear motors, while the 20 mOhm RDS(on) keeps I2R heating manageable in continuous-run applications such as electric bicycles and power tools. The 120 nC gate charge allows PWM frequencies up to 25 kHz with standard gate drivers. Place a flyback diode across the motor and ensure the source tab is soldered to at least 1 sq-in of copper for thermal relief.
Recommended
Synchronous Rectifier in DC-DC Converters
The IRF4905STRLPBF can replace Schottky diodes in low-voltage buck converter synchronous-rectifier positions, reducing conduction loss by up to 50%. At 30A output current and VGS = -10V drive, conduction loss is approximately 18W versus 30W for a comparable 100A Schottky. The P-channel configuration eliminates the need for a bootstrap circuit on the high-side gate drive, simplifying the controller. Its 55V VDS rating supports 24V-input converters and 48V telecom bus applications with appropriate derating for transients.
Recommended
Hot-Swap / Inrush Limiting Circuit
Hot-swap controller circuits use the IRF4905STRLPBF as the series pass element that limits inrush current when a board is plugged into a live backplane. The P-channel orientation allows the gate to be pulled up by the input supply, blocking current until a controller IC releases the gate to ground through a controlled ramp. The 20 mOhm RDS(on) keeps steady-state voltage drop below 50 mV at 2.5A, minimizing power dissipation on the motherboard. The 170W power rating provides substantial transient headroom for capacitive loads up to 1000 uF.
Recommended
Battery Management / Power ORing
In redundant battery systems, the IRF4905STRLPBF implements back-to-back ORing switches that disconnect a failing battery from the load bus. The P-channel high-side configuration blocks reverse current flow while the low RDS(on) minimizes voltage drop during normal parallel operation. At 30A continuous current per battery, the MOSFET dissipates only 18W versus 60W for a Schottky-diode ORing scheme. The 55V VDS rating supports 48V telecom battery plants with appropriate headroom for transient surges.
Recommended
Industrial Load Switch / Power Distribution
Industrial PLCs and process controllers use the IRF4905STRLPBF as a 24V/36V load switch that disconnects field wiring from the central controller. The P-channel high-side placement allows on/off control via a single GPIO pin and a small gate resistor. With 74A continuous current, a single MOSFET handles 1.5 kW of switched load at 24V, sufficient for solenoid valves, motor starters, and resistive heaters. The 175C maximum junction temperature supports enclosed control cabinets without active cooling, and the D2PAK package survives standard industrial vibration profiles.
Recommended
Recommended Products Summary
Engineering reference data for IRF4905STRLPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRF4905STRLPBF-Q1 | IRF4905STRRPBF | IRF4905SPBF | IRF4905STRPBF | FDD6637 |
|---|---|---|---|---|---|---|
| Package | D2PAK (TO-263) | D2PAK (TO-263) - same | D2PAK (TO-263) - same | D2PAK (TO-263) - same | D2PAK (TO-263) - same | DPAK (TO-252) |
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon | onsemi |
| Drain-Source Voltage (VDS) | -55 V | -55 V | -55 V | -55 V | -55 V | -60 V |
| Continuous Drain Current (Tc=25C) | -74 A | -74 A | -74 A | -74 A | -74 A | -55 A |
| On-Resistance RDS(on) at VGS=-10V | 20 mOhm | 20 mOhm | 20 mOhm | 20 mOhm | 20 mOhm | 30 mOhm |
| Total Gate Charge (Qg) | 120 nC | 120 nC | 120 nC | 120 nC | 120 nC | [DATA_NEEDED] |
| Power Dissipation (Tc=25C) | 170 W | 170 W | 170 W | 170 W | 170 W | [DATA_NEEDED] |
| Automotive Grade (AEC-Q100) | No | Yes | No | No | No | No |
Key Differentiators
- Lowest on-resistance in its voltage class (vs FDD6637)
- Automotive-qualified variant available in same package (vs IRF4905STRRPBF)
- Higher continuous current rating than competing P-channel MOSFETs (vs FDD6637)
Design Notes
Estimated: At ID = 30A and RDS(on) = 20 mOhm, conduction loss is approximately 18W (I^2 x R). The D2PAK package has a junction-to-case thermal resistance of approximately 0.9 C/W (per datasheet), so the junction rises 16C above the case. For a typical PCB layout with 1 sq-in of copper, the junction-to-ambient resistance is approximately 62 C/W, leading to a total Tj of 25C + 18W x 62 C/W = 25C + 1116C - which is far above the 175C limit. At 30A continuous, active heatsinking or forced-air cooling is mandatory; at 5A continuous the part runs cool without external heatsink.
The D2PAK drain tab is the primary thermal dissipation path and must be soldered to a PCB copper pour of at least 1 square inch (645 sq-mm) on the top layer, with thermal vias connecting to inner copper planes. Keep the source trace short to minimize parasitic inductance in switching applications. Gate trace should be routed away from drain-source switching nodes and protected from dv/dt coupling with a 10 kOhm gate-source pulldown resistor (per manufacturer application note guidance).
Do not drive the gate with logic-level signals (3.3V or 5V) - the IRF4905STRLPBF requires VGS = -10V to achieve the specified 20 mOhm RDS(on). At VGS = -5V the channel is only partially enhanced and RDS(on) increases to 50-80 mOhm, causing excessive heating. Use a gate-driver IC or a charge-pump circuit capable of swinging to at least -10V relative to source. Also, the absolute maximum VGS is ±20V; add a Zener clamp (15V) gate-to-source to protect against transient overvoltage from Miller-effect coupling during fast switching transitions.
Compliance Information
Standard IRF4905STRLPBF is not AEC-Q100 qualified - choose IRF4905STRLPBF-Q1 for automotive. RoHS and lead-free compliant per Infineon product page; MSL 1 per JEDEC J-STD-020.
