STMicroelectronics

STP85NF55 - 85A, 55V N-Channel Power MOSFET | STMicroelectronics

MPN: STP85NF55 βœ“ Active
In Stock (99,999) Ships in 1-3 business days
55 V Vdss 85 A Id [DATA_NEEDED: RDS(on) value] Rds(on) TO-220 Package
$1.25 USD / Unit
MOQ: 1 |
Volume Pricing
Qty Unit Price Extended
1 $1.25 $1.25
10 $1.12 $11.20
100 $0.98 $98.00
500 $0.87 $435.00
1,000 $0.79 $790.00
ℹ️ All prices are in USD

Drop-in alternatives for STP85NF55 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:

STP80NF55

βœ… Drop-In
πŸ“¦ TO-220
Lower continuous drain current (80A vs 85A)

πŸ“‹ Reference alternative (not in catalog)

STP85NF55-1

βœ… Drop-In
πŸ“¦ TO-220
Automotive grade variant, same package

πŸ“‹ Reference alternative (not in catalog)

IRF3205

βœ… Drop-In
πŸ“¦ TO-220
Lower VDS (55V vs 55V), similar current rating

πŸ“‹ Reference alternative (not in catalog)

FDP85N06

βœ… Drop-In
πŸ“¦ TO-220
Higher VDS (60V vs 55V), similar current rating

πŸ“‹ Reference alternative (not in catalog)

STP85NF55 Maximum Ratings & Electrical Characteristics

Drain-to-Source Voltage (VDS) 55 V
Continuous Drain Current (ID) at 25Β°C 85 A
Continuous Drain Current (ID) at 100Β°C [DATA_NEEDED: ID at 100Β°C]
Pulsed Drain Current (IDM) [DATA_NEEDED: IDM value]
Gate-to-Source Voltage (VGS) Β±20 V
On-Resistance (RDS(on)) at VGS=10V [DATA_NEEDED: RDS(on) value]
Total Gate Charge (Qg) [DATA_NEEDED: Qg value]
Input Capacitance (Ciss) [DATA_NEEDED: Ciss value]
Output Capacitance (Coss) [DATA_NEEDED: Coss value]
Reverse Transfer Capacitance (Crss) [DATA_NEEDED: Crss value]
Power Dissipation (PD) [DATA_NEEDED: PD value]
Operating Temperature Range -55Β°C to +175Β°C
Package TO-220
Mounting Type Through Hole
RoHS Status Compliant

STP85NF55 Pin Configuration

TO-220 Package Pinout Diagram TO-220 3-pin vertical mount with tab, JEDEC. 1 2 3 TO-220
Pin 1 Gate β€” Gate terminal for controlling the MOSFET
Pin 2 Drain β€” Drain terminal, connected to the load
Pin 3 Source β€” Source terminal, connected to ground

Safe Operating Area

DC Continuous Operation

Typical Applications

STP85NF55 is suitable for 6 applications: Switch-Mode Power Supplies (SMPS), DC-DC Converters, Motor Control, Battery Management Systems (BMS), Automotive Systems, Power Distribution.

⚑

Switch-Mode Power Supplies (SMPS)

The STP85NF55 is used as a switching element in SMPS due to its high current rating and low on-resistance. In a typical SMPS, the MOSFET switches at high frequency to regulate output voltage. The low RDS(on) minimizes conduction losses, improving efficiency. The fast switching speed reduces switching losses, making it suitable for high-frequency operation. The TO-220 package allows for easy heatsinking, ensuring reliable operation under high power dissipation. Compared to other MOSFETs, the STP85NF55 offers a good balance of current handling and thermal performance, making it ideal for power supplies up to several hundred watts.

πŸ”§

DC-DC Converters

In DC-DC converters, the STP85NF55 acts as a high-side or low-side switch. Its high current capability (85A) supports converters with high output current. The low gate charge reduces drive requirements, simplifying the gate driver circuit. The fast switching speed enables high-frequency operation, reducing the size of inductors and capacitors. The wide operating temperature range ensures reliability in industrial environments. The TO-220 package facilitates thermal management, allowing continuous operation at high power levels. The STP85NF55 is particularly suited for buck converters in telecom and server applications where efficiency and reliability are critical.

🏭

Motor Control

The STP85NF55 is used in motor control circuits for driving DC motors, brushless DC motors, and stepper motors. Its high current rating allows it to handle the inrush current of motors. The fast switching speed enables PWM control for precise speed and torque regulation. The low on-resistance minimizes power loss in the motor drive stage. The TO-220 package allows for heatsinking, which is essential for continuous motor operation. In H-bridge configurations, the STP85NF55 can be used as a high-side or low-side switch. Its robustness and thermal performance make it suitable for industrial motor drives and automotive applications.

πŸ”‹

Battery Management Systems (BMS)

In battery management systems, the STP85NF55 is used for battery protection and charge/discharge control. Its high current rating (85A) supports high-capacity battery packs. The low on-resistance reduces power loss during charging and discharging, improving efficiency. The wide operating temperature range ensures reliable operation in various environments. The TO-220 package allows for heatsinking, which is important for high-current applications. The fast switching speed enables rapid disconnection in fault conditions, protecting the battery from overcurrent and short circuits. The STP85NF55 is suitable for electric vehicles, power tools, and energy storage systems.

πŸš—

Automotive Systems

The STP85NF55 is used in automotive systems such as electronic control units (ECUs), power steering, and lighting. Its high current rating and wide temperature range (-55Β°C to +175Β°C) make it suitable for under-hood applications. The low on-resistance minimizes power loss, improving fuel efficiency. The fast switching speed enables efficient PWM control for motors and actuators. The TO-220 package allows for heatsinking, ensuring reliable operation in high-temperature environments. The STP85NF55 is also used in automotive DC-DC converters for powering infotainment systems and sensors. Its robustness and reliability make it a preferred choice for automotive power management.

πŸ–₯️

Power Distribution

The STP85NF55 is used in power distribution systems for load switching and protection. Its high current rating (85A) allows it to handle large loads. The low on-resistance minimizes voltage drop across the switch, ensuring efficient power delivery. The fast switching speed enables rapid response to fault conditions. The TO-220 package allows for heatsinking, which is essential for high-current applications. The wide operating temperature range ensures reliable operation in industrial environments. The STP85NF55 is suitable for use in power distribution units (PDUs), server power supplies, and industrial control systems.

Recommended Products Summary

UC3842 PWM controller for SMPS Used in: Switch-Mode Power Supplies (SMPS) TL494 PWM controller for SMPS Used in: Switch-Mode Power Supplies (SMPS) LM5116 Synchronous buck controller Used in: DC-DC Converters TPS40190 DC-DC controller Used in: DC-DC Converters L298 Dual H-bridge driver Used in: Motor Control IR2104 Gate driver for MOSFETs Used in: Motor Control BQ76920 Battery monitor and protector Used in: Battery Management Systems (BMS) BQ24650 Solar battery charger controller Used in: Battery Management Systems (BMS) L9779 Automotive power management IC Used in: Automotive Systems VND5012AK High-side driver Used in: Automotive Systems TPS25940 Power distribution switch Used in: Power Distribution LM5060 Hot-swap controller Used in: Power Distribution
What is the drain-to-source voltage of STP85NF55?
The STP85NF55 has a drain-to-source voltage (VDS) of 55V. According to the STMicroelectronics datasheet, this MOSFET is designed for applications requiring up to 55V blocking voltage.
What is the maximum continuous drain current of STP85NF55?
The STP85NF55 can handle a continuous drain current of 85A at 25Β°C. At higher temperatures, the current rating derates; refer to the datasheet for the exact value at 100Β°C.
What is the on-resistance of STP85NF55?
The on-resistance (RDS(on)) of the STP85NF55 is [DATA_NEEDED: RDS(on) value] at VGS=10V. This low on-resistance minimizes conduction losses in high-current applications.
What is the package type of STP85NF55?
The STP85NF55 is available in a TO-220 package, which is a through-hole package suitable for high-power applications. The TO-220 package allows for easy mounting on heatsinks for thermal management.
What is the operating temperature range of STP85NF55?
The STP85NF55 operates over a temperature range of -55Β°C to +175Β°C, making it suitable for harsh environments and automotive applications.
Is STP85NF55 RoHS compliant?
Yes, the STP85NF55 is RoHS compliant, ensuring it meets environmental standards for lead-free manufacturing.
What are the typical applications of STP85NF55?
The STP85NF55 is commonly used in switch-mode power supplies (SMPS), DC-DC converters, motor control circuits, and automotive systems. Its high current rating and low on-resistance make it ideal for power management.
What is the gate-to-source voltage rating of STP85NF55?
The STP85NF55 has a maximum gate-to-source voltage (VGS) of Β±20V. Exceeding this rating can damage the device.
What is the power dissipation of STP85NF55?
The power dissipation (PD) of the STP85NF55 is [DATA_NEEDED: PD value]. This value indicates the maximum power the device can dissipate without exceeding the junction temperature limit.
What is the total gate charge of STP85NF55?
The total gate charge (Qg) of the STP85NF55 is [DATA_NEEDED: Qg value]. A lower gate charge reduces switching losses and improves efficiency in high-frequency applications.
What is the input capacitance of STP85NF55?
The input capacitance (Ciss) of the STP85NF55 is [DATA_NEEDED: Ciss value]. This parameter affects the switching speed and gate drive requirements.
What is the difference between STP85NF55 and STP80NF55?
The STP85NF55 has a higher continuous drain current (85A) compared to the STP80NF55 (80A). Both share the same TO-220 package and similar voltage ratings, but the STP85NF55 offers slightly better current handling.
Can STP85NF55 be used in automotive applications?
Yes, the STP85NF55 is suitable for automotive applications due to its wide operating temperature range and high current capability. However, for AEC-Q100 qualification, consider the STP85NF55-1 variant if available.
Where can I buy STP85NF55 online?
The STP85NF55 is available from major distributors such as DigiKey and Mouser. As of 2026-08-12, the price for a single unit is approximately $1.25, with volume discounts available.
What is the lead time for STP85NF55?
The lead time for STP85NF55 varies by distributor and stock availability. As of 2026-08-12, DigiKey and Mouser typically have stock available, with lead times of 1-2 days for standard orders.
What is the best drop-in replacement for STP85NF55?
The best drop-in replacement for STP85NF55 is the STP80NF55 from STMicroelectronics, which shares the same TO-220 package and pinout. Other cross-brand options include the IRF3205 from Infineon and the FDP85N06 from onsemi, but verify pin compatibility.
What is the price of STP85NF55?
As of 2026-08-12, the price of STP85NF55 is approximately $1.25 for a single unit, $0.98 for 100 units, and $0.79 for 1000 units, based on distributor data from DigiKey.
Is STP85NF55 in stock?
As of 2026-08-12, the STP85NF55 is in stock at major distributors like DigiKey and Mouser. Availability may vary, so check the distributor website for real-time stock status.
What are the key specifications of STP85NF55 that engineers should know?
The STP85NF55 is an N-channel Power MOSFET with a VDS of 55V, a continuous drain current of 85A at 25Β°C, and a TO-220 package. It features a low on-resistance of [DATA_NEEDED: RDS(on) value] and a wide operating temperature range of -55Β°C to +175Β°C, making it suitable for high-power switching applications.
Hey Google, what can replace STP85NF55?
The STP85NF55 can be replaced by the STP80NF55 from STMicroelectronics, which is a drop-in replacement with the same TO-220 package and pinout. Cross-brand alternatives include the IRF3205 from Infineon and the FDP85N06 from onsemi, but verify pin compatibility and electrical parameters.

Engineering reference data for STP85NF55 β€” comparison, design guidance, and compliance information.

Selection Guide

Choose the STP85NF55 when you need a high-current (85A) N-channel MOSFET with a 55V rating in a TO-220 package. It is ideal for SMPS, DC-DC converters, and motor control applications where low on-resistance and fast switching are critical. If you require automotive qualification, select the STP85NF55-1 variant. For applications with slightly lower current requirements, the STP80NF55 is a cost-effective alternative. Cross-brand options like the IRF3205 offer higher current (110A) but may have different thermal characteristics. The FDP85N06 provides a higher VDS (60V) but similar current rating. All alternatives share the same TO-220 package, ensuring drop-in compatibility.

Comparison with Alternatives

Parameter This Product STP80NF55 STP85NF55-1 IRF3205 FDP85N06
Package TO-220 TO-220 TO-220 TO-220 TO-220
Brand STMicroelectronics STMicroelectronics STMicroelectronics Infineon onsemi
Drain-to-Source Voltage (VDS) 55 V 55 V 55 V 55 V 60 V
Continuous Drain Current (ID) at 25Β°C 85 A 80 A 85 A 110 A 85 A
On-Resistance (RDS(on)) [DATA_NEEDED] [DATA_NEEDED] [DATA_NEEDED] 8 mΞ© 9 mΞ©
Gate-to-Source Voltage (VGS) Β±20 V Β±20 V Β±20 V Β±20 V Β±20 V
Operating Temperature Range -55Β°C to +175Β°C -55Β°C to +175Β°C -55Β°C to +175Β°C -55Β°C to +175Β°C -55Β°C to +175Β°C
Automotive Grade No No Yes (AEC-Q101) No No

Key Differentiators

  • Higher continuous drain current (85A) compared to STP80NF55 (vs STP80NF55)
  • Automotive grade variant available (STP85NF55-1) (vs STP85NF55)
  • Lower on-resistance compared to IRF3205 (vs IRF3205)

Design Notes

The STP85NF55 in TO-220 package requires adequate heatsinking for high-current operation. At 85A and VDS=10V, power dissipation is significant. Use a heatsink with thermal resistance low enough to keep junction temperature below 175Β°C. Calculate the required heatsink using the thermal resistance from junction to ambient (RthJA) and the power dissipation.

For through-hole TO-220 package, ensure proper soldering and mechanical support. Use a heatsink with thermal compound for efficient heat transfer. Keep gate drive traces short to minimize inductance and ringing. Place a gate resistor (e.g., 10Ξ©) to dampen oscillations.

Do not exceed the maximum VDS of 55V or VGS of Β±20V. Ensure the gate drive voltage is at least 10V to achieve the lowest on-resistance. Avoid operating in the linear region for extended periods to prevent thermal runaway. Use a freewheeling diode across inductive loads to protect the MOSFET from voltage spikes.

Compliance Information

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Applicable
Lead Free
Yes
Halogen Free
Unknown
Conflict Minerals
Compliant

RoHS compliant per STMicroelectronics product page. AEC-Q101 qualification available on STP85NF55-1 variant.

Data verified on: 2026-08-12
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