IRF2805PBF - 55V 175A N-Channel HEXFET MOSFET | Infineon
MPN: IRF2805PBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.45 | $24.50 |
| 100 | $2.05 | $205.00 |
| 500 | $1.75 | $875.00 |
| 1,000 | $1.55 | $1,550.00 |
| 3,000 | $1.38 | $4,140.00 |
IRF2805PBF Overview
An N-channel power MOSFET is a voltage-controlled semiconductor switch that conducts current between drain and source when a positive gate-to-source voltage is applied. It belongs to the power MOSFET family within the broader class of discrete semiconductors and is widely used as the active switching element in DC-DC converters, motor drives, and power management circuits where high efficiency and fast switching are required.
Key features of the IRF2805PBF include a 175 °C maximum junction operating temperature, fast switching speed, and an improved repetitive avalanche rating for rugged inductive switching. The device offers exceptionally low on-resistance per silicon area, making it one of the most efficient 55 V-class TO-220 MOSFETs for high-current applications. The threshold voltage is specified at 4 V, with a guaranteed low on-resistance at VGS = 10 V.
The IRF2805PBF is specifically designed for automotive and heavy industrial applications, combining HEXFET power MOSFET technology with a robust TO-220AB package that supports through-hole mounting and efficient thermal dissipation via the metal tab. Its low RDS(on) minimizes conduction losses, while the fast body diode and avalanche capability improve reliability under harsh switching transients.
Typical applications include high-current DC motor drives, automotive power switching (battery management, ignition, and load control), uninterruptible power supplies (UPS), high-power synchronous rectifiers, welding equipment, and industrial inverters. The 55 V drain-to-source rating also makes it suitable for 12 V and 24 V automotive bus systems.
When designing with this device, ensure that the gate drive voltage reaches at least 10 V to achieve the rated 4.7 mOhm RDS(on). Proper heatsinking is critical because, at 75 A continuous, conduction losses can exceed 25 W; the TO-220AB tab should be mounted to a chassis or external heatsink with thermal compound.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers select, source, and integrate the IRF2805PBF with confidence.
Drop-in alternatives for IRF2805PBF — 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 IRF2805PBF (same form factor and footprint) — differing in Technology, Package, Drain-Source Voltage (VDS), Operating Junction Temperature, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
IRFB3207PBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRF3205PBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRFB3006PBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRFB3077PBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRFB4110PBF
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →IRFB4020PBF
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →IRF2805PBF Maximum Ratings & Electrical Characteristics
| Manufacturer | Infineon Technologies (formerly International Rectifier) |
| Part Number | IRF2805PBF |
| FET Type | N-Channel |
| Technology | HEXFET Power MOSFET (IR MOSFET) |
| Drain-to-Source Voltage (VDS) | 55 V |
| Continuous Drain Current (ID) at Tc | 75 A |
| Continuous Drain Current (ID) at 25°C | 175 A (pulsed / package-limited) |
| On-Resistance RDS(on) max @ VGS=10V | 4.7 mOhm |
| Gate Threshold Voltage (VGS(th)) | 4 V |
| Total Gate Charge (Qg) | 150 nC |
| Power Dissipation (PD) at Tc | 330 W |
| Maximum Junction Temperature | 175 °C |
| Package | TO-220AB (3-pin, through-hole) |
| Mounting Type | Through Hole |
| RoHS Status | Compliant (Pb-free) |
| Operating Temperature Range | -55 °C to +175 °C |
| Configuration | Single N-Channel MOSFET |
IRF2805PBF Pin Configuration
| Pin 1 | Gate — Gate control input; drive to 10 V for full RDS(on) |
| Pin 2 | Drain — Drain terminal (also connected to metal tab) |
| Pin 3 | Source — Source terminal; power return path |
Safe Operating Area (DC)
Typical Applications
IRF2805PBF is suitable for 6 applications: Automotive 12V/24V High-Current Switching, DC Motor Drive (H-Bridge / Half-Bridge), Synchronous Rectifier in 24V DC-DC Converters, Uninterruptible Power Supply (UPS) and Battery Backup, Inductive Load Switching (Solenoids, Relays, Coils), Welding Equipment and High-Power Pulse Applications.
Automotive 12V/24V High-Current Switching
The IRF2805PBF is ideally suited for automotive 12 V and 24 V bus switching thanks to its 55 V VDS rating (with comfortable margin above 24 V transients), 75 A continuous drain current at Tc, and exceptionally low 4.7 mOhm RDS(on). In a battery management or load-switching circuit, the MOSFET is placed between the battery rail and the downstream load (lighting, HVAC blower, fuel pump, or seat heater), controlled by a microcontroller GPIO or driver IC through a 10 V gate-drive signal. The 175 °C junction rating and automotive-grade HEXFET process ensure reliability under under-hood thermal stress. Compared to a relay, the IRF2805PBF eliminates contact wear and EMI arcing, and versus smaller MOSFETs, it dramatically reduces conduction loss at 30-50 A continuous loads.
Recommended
DC Motor Drive (H-Bridge / Half-Bridge)
The IRF2805PBF excels in brushed DC motor drive topologies as the low-side or high-side switch in an H-bridge. Its 4.7 mOhm RDS(on) minimizes conduction loss at 20-40 A motor currents, while the 150 nC gate charge allows PWM switching up to 50 kHz for smooth speed control. A typical application pairs two IRF2805PBF low-side FETs with two P-channel or high-side N-channel drivers, controlled by a half-bridge driver such as the IR2304SPBF or IRS21867STRPBF. The 55 V VDS rating handles motor back-EMF spikes comfortably, and the avalanche rating absorbs regenerative energy during braking. The TO-220AB package is easily mounted to a chassis heatsink for high-duty-cycle industrial motor control up to several horsepower.
Recommended
Synchronous Rectifier in 24V DC-DC Converters
In 24 V-input buck or forward converters, the IRF2805PBF serves as the synchronous rectifier (low-side switch) replacing a Schottky diode. At 30 A output current, the 4.7 mOhm RDS(on) dissipates only about 4.2 W, compared to roughly 18 W for a comparable 40 V Schottky, cutting rectifier losses by 75% and eliminating the need for large heatsinks. The 55 V VDS provides 130% margin above the 24 V input, withstanding ringing and transients on the switching node. The 150 nC gate charge is moderate for a TO-220 part, allowing efficient PWM operation at 100-300 kHz when paired with a synchronous buck controller. The TO-220AB tab provides a low-thermal-resistance path for continuous high-current rectification.
Recommended
Uninterruptible Power Supply (UPS) and Battery Backup
The IRF2805PBF is well-suited for UPS battery-disconnect and inverter switching, where its 55 V VDS handles 48 V telecom battery stacks with margin, and the 75 A continuous rating supports 2-3 kVA inverter stages. In a typical online UPS, two IRF2805PBF units form the low-side switches of a full-bridge inverter stage, switching at 20-50 kHz to convert the 48 V battery bus to 120/230 VAC through a toroidal transformer. The avalanche rating provides robustness against inductive kickback during abnormal load transients, and the 175 °C junction rating tolerates sustained overload conditions. The Pb-free TO-220AB package meets RoHS requirements for commercial and industrial UPS installations.
Recommended
Inductive Load Switching (Solenoids, Relays, Coils)
The IRF2805PBF is ideal for switching inductive loads such as DC solenoids, relay coils, and electromagnetic valves, where the 55 V VDS comfortably absorbs flyback spikes (typically clamped at 1-2x the supply voltage), and the avalanche rating safely dissipates stored inductive energy. A typical application uses the IRF2805PBF as a low-side switch for a 24 V solenoid, with a flyback diode or TVS clamp across the coil to limit drain voltage. The 75 A continuous rating handles inrush currents of large solenoids and contactors. The fast switching speed enables PWM proportional control of solenoid force, and the rugged HEXFET construction provides millions of switching cycles for industrial automation and process control equipment.
Recommended
Welding Equipment and High-Power Pulse Applications
The IRF2805PBF's 175 A pulsed drain current, 4.7 mOhm RDS(on), and high avalanche rating make it a strong candidate for spot-welding and pulsed-power applications. In a typical capacitive discharge welding circuit, multiple IRF2805PBF units are paralleled to switch kiloamp peak currents from a charged capacitor bank into the welding transformer primary. The extremely low on-resistance limits I²R losses during the millisecond-scale welding pulse, while the rugged avalanche capability absorbs the inductive kickback when the pulse terminates. The TO-220AB package allows easy paralleling on a shared heatsink, and the 175 °C junction rating supports the high instantaneous power dissipation typical of pulse applications. The automotive-grade HEXFET process ensures long-term reliability in production welding environments.
Recommended
Recommended Products Summary
Engineering reference data for IRF2805PBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRFB3207PBF | IRF3205PBF | IRFB3006PBF | IRFB3077PBF | IRFB4110PBF | IRFB4020PBF |
|---|---|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | TO-220AB | TO-220AB - same | TO-220AB - same | TO-220AB - same | TO-220AB - same | TO-220AB - same | TO-220AB - same |
| VDS max (V) | 55 V | 75 V | 55 V | 60 V | 75 V | 100 V | 200 V |
| RDS(on) max @ VGS=10V (mOhm) | 4.7 mOhm | 4.5 mOhm | 8.0 mOhm | 2.5 mOhm | 3.3 mOhm | 4.5 mOhm | 70 mOhm |
Key Differentiators
- Among the lowest RDS(on) for a 55 V TO-220AB MOSFET (vs IRF3205PBF)
- Higher VDS margin than 40 V-class ultra-low-RDS parts (vs IRF1404ZPBF)
- Through-hole TO-220AB form factor for robust mechanical mounting (vs IRF2805S (D2PAK))
Design Notes
Estimated: at ID = 50 A continuous with VGS = 10 V, conduction loss Pcond = I² × RDS(on) = 50² × 0.0047 = 11.75 W. The TO-220AB junction-to-ambient thermal resistance with a small clip-on heatsink is approximately 25 °C/W, producing a 294 °C junction temperature rise above 25 °C ambient - well above the 175 °C limit. For continuous operation above 20 A, mount the TO-220 tab to a chassis or external heatsink with thermal compound; aim for theta_SA ≤ 5 °C/W to keep Tj under 150 °C at full load.
Keep the gate-drive loop (gate-driver output → gate → source → gate-driver ground) as small as possible to minimize parasitic inductance that causes ringing and gate-overshoot. Use a 10 Ohm gate resistor for typical applications to dampen ringing. Place a 100 kohm pull-down resistor from gate to source to ensure the MOSFET stays off when the driver is high-impedance (e.g., during MCU reset). For switching frequencies above 100 kHz, use a dedicated gate driver such as IR2304SPBF rather than driving directly from a microcontroller GPIO.
Do not drive the gate with less than 10 V - the IRF2805PBF's RDS(on) is specified at VGS = 10 V, and at 5 V the on-resistance can be 2-3x higher, dramatically increasing conduction loss. Do not exceed VGS = 20 V (absolute max). When switching inductive loads, add a freewheeling diode or TVS clamp to limit drain voltage below 55 V; the body diode alone has slow reverse recovery and may cause dv/dt-induced turn-on in half-bridge topologies.
When using the TO-220AB through-hole package, ensure the PCB hole diameter is 0.9-1.0 mm for the leads and the mounting hole is 3.6-3.8 mm for the tab screw. Provide at least 2 oz copper on drain and source pads to handle the high current. If the tab is bolted to a heatsink, isolate the tab with a thermal pad (Bergquist or similar) and a plastic shoulder washer if the heatsink is electrically live, since the tab is internally connected to the Drain.
Compliance Information
Pb-free (PBF suffix indicates lead-free plating). RoHS compliant per Infineon product page. The part was originally designed for automotive applications per the datasheet description, but specific AEC-Q100 qualification status was not confirmed in the provided web data and is marked as not_applicable; for AEC-Q100 qualified automotive sourcing, contact Infineon directly or use the AU-prefix equivalent parts.
