IRF4905LPBF - P-Ch -55V 74A 20mOhm HEXFET MOSFET | Infineon
MPN: IRF4905LPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.72 | $17.20 |
| 100 | $1.45 | $145.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.98 | $980.00 |
Drop-in alternatives for IRF4905LPBF — 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:
IRF4905PBF
✅ Drop-In✓ In Stock
$0.95 / Unit
View Datasheet →IRF4905SPBF
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →IRF4905STRLPBF
✅ Drop-In✓ In Stock
$0.95 / Unit
View Datasheet →IRF4905LPBF
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →FQP27P06
✅ Drop-In📋 Reference alternative (not in catalog)
IRF4905LPBF Maximum Ratings & Electrical Characteristics
| Polarity | P-Channel |
| Drain-Source Voltage (Vds) | -55 V |
| Continuous Drain Current (Id) @ Tc=25C | -74 A |
| On-Resistance Rds(on) max @ Vgs=-10V | 20 mOhm |
| Gate-Source Voltage (Vgs) max | ±20 V |
| Total Power Dissipation (Ptot) @ Tc=25C | 200 W |
| Operating Junction Temperature | -55C to +150C |
| Package | TO-262 (I2PAK), through-hole, 3-pin |
| Technology | HEXFET (IR MOSFET) |
| Mounting Type | Through Hole |
| Lead-Free / RoHS | Yes (PbF suffix) |
| Avalanche Rated | Yes |
IRF4905LPBF Pin Configuration
| Pin 1 | Gate — Gate control input; drive 0V relative to source to turn on, Vsource to turn off |
| Pin 2 | Drain — Drain terminal; connected to load for high-side P-channel switching |
| Pin 3 | Source — Source terminal; tied to positive supply rail for high-side P-channel configuration |
| Pin TAB | Drain — Metal tab is internally connected to Drain (pin 2); used for heatsink mounting |
Safe Operating Area (DC, Tc=25C)
Typical Applications
IRF4905LPBF is suitable for 6 applications: Automotive Reverse-Battery Protection, High-Side Load Switch in 12V/24V Systems, DC Motor and Solenoid Driver, Battery Disconnect in UPS Systems, Solar Charge Controller Reverse-Current Blocking, Hot-Swap and Inrush Limiting.
Automotive Reverse-Battery Protection
The IRF4905LPBF's P-channel polarity and -55V Vds rating make it ideal for reverse-battery protection in 12V automotive systems. With source tied to +12V battery and drain to the load, the MOSFET conducts under normal polarity when the gate is pulled low (low-side driver), and self-blocks under reverse polarity because Vgs is forced positive beyond the safe operating area. The 20 mOhm Rds(on) limits continuous conduction loss to about 4.8W at 20A, far lower than Schottky-diode alternatives, while the 74A current rating handles inrush from capacitive loads. The TO-262 package allows screw-mount heatsinking in engine-bay enclosures and offers mechanical robustness under automotive vibration per typical AEC-Q100 environmental expectations for non-safety power circuits.
Recommended
High-Side Load Switch in 12V/24V Systems
The IRF4905LPBF simplifies high-side switching by eliminating the charge pump or bootstrap required by N-channel MOSFETs. In a 24V industrial system, pulling the gate to ground (0V referenced to source) drives Vgs to -24V, well beyond the threshold, providing low Rds(on) and full enhancement. The 20 mOhm on-resistance at 74A rating allows switching of multi-amp loads with minimal heat dissipation. Compared to mechanical relays, the IRF4905LPBF switches in microseconds, eliminates contact bounce, and supports PWM dimming or soft-start. The TO-262 long-lead package mounts directly to a small clip-on heatsink in space-constrained distribution boxes and PLC output modules.
Recommended
DC Motor and Solenoid Driver
The IRF4905LPBF handles inductive loads like DC motors and solenoids thanks to its avalanche energy rating and 74A pulsed current capability. In a PWM-driven motor control loop, the MOSFET switches at 1-25 kHz with body-diode freewheeling through an external Schottky or synchronous FET, while the IRF4905LPBF switches the high side directly from the 12V/24V rail. The 20 mOhm Rds(on) keeps I²R conduction loss manageable at high duty cycles - for example at 30A continuous, loss is 18W. The TO-262 through-hole package withstands the mechanical shock and thermal cycling of automotive underhood or industrial actuator environments better than SMD alternatives.
Recommended
Battery Disconnect in UPS Systems
Uninterruptible power supplies use the IRF4905LPBF as a low-loss battery disconnect switch between the battery pack and the inverter bus. In 48V battery banks (multiple 12V blocks in series), each block is protected by its own IRF4905LPBF or stacked configuration to prevent deep discharge and to isolate faulty cells. The P-channel topology connects source to battery positive and drain to the inverter input; turning the gate off with a pull-up resistor disconnects the battery safely. At 20 mOhm Rds(on), conduction loss is significantly lower than the equivalent Schottky OR-ing diode, raising overall UPS efficiency by 1-3%. The 150C junction rating accommodates the elevated ambient temperature of sealed battery cabinets.
Recommended
Solar Charge Controller Reverse-Current Blocking
In solar charge controllers, the IRF4905LPBF blocks reverse current flow from the battery back to the solar panel at night - a critical function where conventional diodes waste 5-10% of harvested energy. The P-channel MOSFET is placed in series with the positive solar lead; during daylight, Vgs is driven negative (panel above battery), turning the device fully on with only 20 mOhm loss. At night, panel voltage drops below battery voltage, Vgs becomes positive, and the MOSFET self-extinguishes. The 74A rating handles peak solar currents up to 1500W at 24V nominal. The TO-262 package is convection-cooled in typical outdoor NEMA enclosures.
Recommended
Hot-Swap and Inrush Limiting
The IRF4905LPBF serves as the main pass element in 12V/24V hot-swap controllers, where its P-channel high-side topology and -74A rating allow soft-start of large capacitive loads. A gate resistor combined with a Zener clamp ramps Vgs slowly, limiting inrush di/dt to safe levels for downstream bulk capacitors. Once the gate is fully enhanced, Rds(on) of 20 mOhm provides low steady-state loss. The TO-262 long-lead package suits backplane insertion applications where through-hole leads provide stronger mechanical retention than SMD during repeated mating cycles. The 150C junction rating accommodates the inrush heating event.
Recommended
Recommended Products Summary
Engineering reference data for IRF4905LPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRF4905PBF | IRF4905SPBF | IRF4905STRLPBF | FQP27P06 |
|---|---|---|---|---|---|
| Package | TO-262 (I2PAK) | TO-220 | D2PAK (TO-263) | D2PAK (TO-263) | TO-220 |
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | onsemi |
| Polarity | P-Channel | P-Channel | P-Channel | P-Channel | P-Channel |
| Drain-Source Voltage (Vds) | -55 V | -55 V | -55 V | -55 V | -60 V |
| Continuous Drain Current (Id) | -74 A | -74 A | -74 A | -74 A | -27 A |
| Rds(on) max @ Vgs=-10V | 20 mOhm | 20 mOhm | 20 mOhm | 20 mOhm | 70 mOhm |
| Total Power Dissipation | 200 W | 200 W | 200 W | 200 W | [DATA_NEEDED] |
| Mounting Type | Through Hole | Through Hole | Surface Mount | Surface Mount | Through Hole |
| Lead-Free / RoHS | Yes (PbF) | Yes (PbF) | Yes (PbF) | Yes (PbF) | Yes |
Key Differentiators
- Low-profile through-hole variant of the IRF4905 die family (vs IRF4905PBF (TO-220))
- Same die, surface-mount assembly option (vs IRF4905STRLPBF (D2PAK))
- Significantly higher current rating than typical cross-brand P-channel alternative (vs FQP27P06 (onsemi))
Design Notes
Estimated: at 30A continuous load and 20 mOhm Rds(on) at 25C, conduction loss is roughly 18W. Using the typical TO-262 junction-to-case thermal resistance of approximately 0.75 C/W and assuming a clip-on heatsink with 20 C/W to ambient, total junction-to-ambient thermal resistance is ~20.75 C/W, producing a temperature rise of 374C above ambient - well above the 150C limit. Either reduce continuous current, increase heatsink area, or force-air cool. Always validate with a thermocouple on the metal tab in the worst-case operating condition rather than relying on calculated estimates alone.
For high-side P-channel switching, place the gate pull-down resistor (typically 10-100 kOhm) close to the gate pin to prevent floating-gate turn-on during fast dV/dt events. The gate-source Zener clamp (typically 15V) should be placed within 5 mm of the gate pin to limit Vgs transients below the ±20V absolute maximum. Keep the high-current drain-source loop area small to minimize parasitic inductance and ringing; use wide copper pours or bus bars for currents above 20A. The TO-262 metal tab must be isolated from the heatsink if the heatsink is grounded, since the tab is internally connected to the drain.
Do not drive the gate above ±20V relative to source - P-channel gates driven hard positive beyond the safe operating area can fail the gate oxide. Use a gate-source Zener clamp or resistor divider to limit Vgs to a safe level (typically 15V clamp + small series resistor). Do not rely on the body diode for sustained conduction in reverse-polarity applications - the body diode forward drop is high and the silicon is not optimized for it; use an external Schottky for freewheeling instead. Finally, verify that Vgs(th) is within the drive voltage available at the lowest expected operating temperature, since P-channel thresholds can shift upward by 0.5-1V from 25C to -40C.
Compliance Information
PbF suffix confirms lead-free terminal finish and RoHS compliance per manufacturer datasheet. Not formally AEC-Q100 qualified; for AEC-Q100 applications confirm with Infineon automotive-grade part numbering. REACH compliance stated by Infineon product page.
