IRL3705NPBF - 55V 89A N-Channel HEXFET MOSFET | Infineon
MPN: IRL3705NPBF β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.31 | $131.00 |
| 500 | $1.08 | $540.00 |
| 1,000 | $0.92 | $920.00 |
Drop-in alternatives for IRL3705NPBF β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
IRL3705ZPBF
β Drop-Inπ Reference alternative (not in catalog)
IRLI3705N
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
SPP80NF70
β Drop-Inπ Reference alternative (not in catalog)
STP80NF70
β Drop-Inπ Reference alternative (not in catalog)
NTP5860N
β Drop-Inπ Reference alternative (not in catalog)
PSMN0R9-30YLD
β Drop-Inπ Reference alternative (not in catalog)
IRFB7534PBF
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.85 / Unit
View Datasheet βIRL3705NPBF Maximum Ratings & Electrical Characteristics
| FET Type | N-Channel |
| Drain-Source Voltage (V_DS) | 55 V |
| Continuous Drain Current (I_D) at Tc | 89 A |
| Power Dissipation (P_D) at Tc | 170 W |
| On-Resistance R_DS(on) | 10 mOhm (typical, V_GS = 5 V) |
| Total Gate Charge Q_g | 65.3 nC |
| Maximum Junction Temperature | 175 C |
| Technology | HEXFET (planar cell, fifth generation) |
| Package | TO-220AB (3-pin through-hole) |
| Mounting Type | Through Hole |
| Gate Drive Level | Logic-level |
| Avalanche Rated | Yes (ruggedized single-pulse avalanche) |
| Lead-Free (PBF suffix) | Yes |
| RoHS Status | Compliant (per PBF suffix) |
IRL3705NPBF Pin Configuration
| Pin 1 | Gate β Logic-level gate input (enhance at V_GS = 5 V) |
| Pin 2 | Drain β Drain terminal, electrically tied to metal mounting tab |
| Pin 3 | Source β Source terminal |
IRL3705NPBF Safe Operating Area (DC)
Typical Applications
IRL3705NPBF is suitable for 7 applications: DC Motor Drive (H-Bridge), Solenoid and Relay Switching, Battery Protection / Load Switch, Low-Voltage DC-DC Converter (Synchronous Rectifier), Uninterruptible Power Supply (UPS) Output Stage, Industrial Soldering Iron / Hot-Air Tool Power Control, Automotive Auxiliary Load Switch.
DC Motor Drive (H-Bridge)
The IRL3705NPBF suits DC motor H-bridge half-bridges and forward/reverse drives at 12-24 V bus, where its 89 A continuous drain rating, 10 mΞ© typical R_DS(on) at V_GS=5 V, and logic-level gate allow direct MCU PWM control without a gate driver. The HEXFET planar-cell structure provides a wide SOA so motor stall transients stay inside the safe region. Used in automotive accessory motors, robotic drive stages, and e-bike controllers, where the TO-220AB tab can be clamped to a chassis-mounted heatsink.
Recommended
Solenoid and Relay Switching
The IRL3705NPBF drives inductive loads such as 12 V and 24 V solenoids, contactors, and latching relays where the avalanche-rated ruggedized silicon absorbs the inductive kickback at turn-off. Its 55 V V_DS gives ample margin over typical 24 V bus transients, and the 10 mΞ© R_DS(on) minimizes steady-state heating when the solenoid is held energized. The logic-level gate permits direct GPIO control from 5 V microcontrollers. The TO-220AB through-hole form factor simplifies hand-soldered prototyping and field-serviceable designs.
Recommended
Battery Protection / Load Switch
The IRL3705NPBF serves as a low-side load-disconnect switch in 12 V lead-acid and multi-cell lithium battery systems, where its 89 A rating covers peak inverter or starter loads and its 10 mΞ© R_DS(on) keeps conduction loss manageable. The avalanche-rated body diode handles reverse-battery jump-start events up to the 55 V V_DS rating, and the logic-level gate allows MCU-controlled cutoff without a pre-driver. Per Infineon's datasheet, the part is qualified to JEDEC standards for reliability in harsh automotive and industrial environments.
Recommended
Low-Voltage DC-DC Converter (Synchronous Rectifier)
The IRL3705NPBF operates as the synchronous-rectifier low-side switch in non-isolated buck converters running at 100-500 kHz from a 24 V or 36 V bus down to 3.3-12 V rails. Its 65.3 nC total gate charge and low R_DS(on) keep switching and conduction losses low, while the planar-cell HEXFET process delivers a tight R_DS(on) tolerance that simplifies current-mode control loop design. For switching above 100 kHz, a dedicated gate driver (e.g., IR2104 family) is recommended to fully exploit the device's switching speed.
Recommended
Uninterruptible Power Supply (UPS) Output Stage
In UPS output stages, the IRL3705NPBF functions as the low-side switch of the inverter leg converting battery DC to AC mains. Its 55 V V_DS and 89 A rating handle 1-2 kVA low-voltage inverter designs, while the avalanche rating absorbs the inductive kickback from the output filter inductor at zero-crossing. The logic-level gate allows the part to be driven directly from a digital controller or a small gate-driver stage. The TO-220AB package accepts through-hole mounting on a chassis heatsink, simplifying manufacturing.
Recommended
Industrial Soldering Iron / Hot-Air Tool Power Control
The IRL3705NPBF works as a low-side PWM switch in 24 V soldering iron and hot-air rework station power controllers, where its 10 mΞ© R_DS(on) at 5 V gate drive minimizes dissipation at high duty cycles and the 89 A current rating covers the inrush of large heating elements. The HEXFET planar-cell structure provides a wide SOA so the part survives heater short-circuit faults within the avalanche rating. The logic-level gate allows direct MCU PID control without a separate driver, simplifying the analog front-end.
Recommended
Automotive Auxiliary Load Switch
The IRL3705NPBF is well suited for switching 12 V and 24 V automotive auxiliary loads such as lighting, seat heaters, and pneumatic pumps, where the 55 V V_DS rating covers load-dump transients up to ~40 V typical. Its logic-level gate allows direct GPIO control from body-domain microcontrollers (3.3 V or 5 V), and the ruggedized HEXFET structure absorbs inductive kickback from relay coils and solenoids. Although not AEC-Q100 qualified by default, the part is widely used in non-safety automotive subsystems with appropriate environmental qualification by the OEM.
Recommended
Recommended Products Summary
Engineering reference data for IRL3705NPBF β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRL3705ZPBF | SPP80NF70 | STP80NF70 | NTP5860N |
|---|---|---|---|---|---|
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies | STMicroelectronics | onsemi |
| Package | TO-220AB | TO-220AB - same | TO-220AB - same | TO-220AB - same | TO-220AB - same |
| V_DS Max | 55 V | 75 V | 75 V | 75 V | 55 V |
| Continuous Drain Current (Tc) | 89 A | [DATA_NEEDED: continuous drain current] | 80 A | 80 A | [DATA_NEEDED: continuous drain current] |
| R_DS(on) typical | 10 mOhm at V_GS=5V | [DATA_NEEDED: R_DS(on)] | 9 mOhm at V_GS=10V | 9.5 mOhm at V_GS=10V | [DATA_NEEDED: R_DS(on)] |
| Total Gate Charge Q_g | 65.3 nC | [DATA_NEEDED: gate charge] | [DATA_NEEDED: gate charge] | [DATA_NEEDED: gate charge] | [DATA_NEEDED: gate charge] |
| Gate Drive Level | Logic-level (5 V) | Logic-level | Standard (10 V) | Standard (10 V) | Logic-level (5 V) |
| Avalanche Rated | Yes | Yes | Yes | Yes | [DATA_NEEDED: avalanche rated] |
| Approx. Unit Price (1 pc) | $1.85 | [DATA_NEEDED: price] | [DATA_NEEDED: price] | [DATA_NEEDED: price] | [DATA_NEEDED: price] |
Key Differentiators
- Logic-level gate drive eliminates pre-driver stage (vs STP80NF70)
- Wide Safe Operating Area for motor stall and short-circuit events (vs NTP5860N)
- Avalanche-rated ruggedized silicon (vs PSMN0R9-30YLD)
- Industry-standard TO-220AB footprint with broad second-source availability (vs IRLI3705N)
Design Notes
At 89 A continuous drain current and a fully-enhanced R_DS(on) of 10 mΞ©, the IRL3705NPBF can dissipate up to P = IΒ² Γ R = 89Β² Γ 0.010 = ~79 W. Per the Infineon datasheet the maximum junction-to-case thermal resistance is approximately 0.88 C/W (TO-220AB). Without a substantial heatsink the junction temperature will exceed 175 Β°C within seconds. Use a heatsink rated for <2 C/W with thermal compound, and isolate the tab electrically with a silicone pad and nylon screw bushing when the heatsink is grounded. Estimated: assumes worst-case R_DS(on) and continuous DC; actual dissipation at typical loads is far lower.
Keep the gate-drive loop area to a minimum by placing the gate-driver output and the gate-source resistor physically close to the MOSFET pins. Source inductance shared with the power ground creates negative feedback that slows switching and may cause ringing above 50 V on the drain at turn-off. Use a Kelvin connection to the source sense pin if available, or place the gate-drive return directly at the source lead rather than at the power ground. The Infinean application note MT-097 (Mounting Considerations for HEXFET Power MOSFETs) provides PCB layout guidance.
Do not connect the metal TO-220AB tab directly to a grounded heatsink without an insulating pad - the tab is electrically tied to the drain, and a short to ground will create a direct short circuit on the bus. Also, do not assume logic-level V_GS(th) implies safe operation below V_GS = 5 V at high currents - R_DS(on) climbs rapidly as V_GS approaches V_GS(th), causing thermal runaway. Always drive the gate to at least 8-10 V when switching large currents at high frequency, or use a charge-pump gate-boost circuit if only 5 V is available. Per Infineon's datasheet, R_DS(on) is specified at V_GS = 5 V but the device is fully enhanced at 10 V.
Through-hole TO-220AB mounting is well-suited for hand-soldered prototypes and high-current applications. Use a minimum 2 oz copper pour on drain and source pads, and provide at least 0.5 inchΒ² of copper area on each side of the package for heat-spreading when a dedicated heatsink is not used. The drain lead and the metal tab share the same node, so the drain PCB pad can extend beneath the package to enhance thermal conduction to inner copper layers. For vibration-prone applications, use a mechanical screw clamp to retain the package against the heatsink.
Compliance Information
Lead-free (PBF suffix) per Infineon product page; RoHS compliant by suffix designation. JEDEC-qualified per Infineon datasheet. Not AEC-Q100 qualified - for automotive safety-critical applications use an AEC-Q100 part such as the BTS70082EPAXUMA1 high-side switch.
