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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

STMicroelectronics STP4NB50

Name: STP4NB50
Brand: STMicroelectronics
SKU: STP4NB50
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STP4NB50

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: STP4NB50.pdf

Description:: MOSFET N-CH 500V 3.8A TO220AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

STP4NB50 from STMicroelectronics is an N-channel enhancement-mode PowerMesh™ MOSFET rated for 500 V drain-source voltage, 2.5 Ω typical R_DS(on) at V_GS = 10 V and I_D = 1.9 A, with 3.8 A continuous drain current at T_C = 25 °C. It features 100% avalanche tested ruggedness, 4.5 V/ns dv/dt capability, and low gate charge (15–21 nC), targeting high-speed switching in industrial SMPS and welding inverters.

For engineers reviewing the STP4NB50 datasheet, STP4NB50 pinout, STP4NB50 application, or STP4NB50 equivalent, key selection criteria include its 500 V breakdown rating, TO-220 package thermal resistance (1.56 °C/W), unclamped inductive avalanche energy (220 mJ), and diode recovery performance (t_rr = 245 ns, Q_rr = 980 nC) under 150 °C junction conditions.

Technical Context

This MOSFET employs ST's proprietary PowerMesh™ process with MESH OVERLAY™ and patented strip layout, delivering minimized intrinsic capacitances (C_iss = 400 pF, C_oss = 62 pF) and ultra-low gate charge to reduce switching losses. Its edge termination structure enables exceptional dv/dt immunity and avalanche robustness without external snubbers.

The device operates as a high-voltage, medium-current power switch with integrated body diode optimized for hard-switched inductive loads. Gate threshold voltage (2–4 V) ensures compatibility with standard 10 V gate drivers, while R_DS(on) remains stable up to T_j = 150 °C, supporting thermally constrained industrial designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	500 V - Withstands DC or peak repetitive drain-source voltages up to 500 V without breakdown.
R_DS(on) (typ)	2.5 Ω @ V_GS = 10 V, I_D = 1.9 A - Enables low conduction loss in 3.8 A continuous switching applications.
I_D (cont)	3.8 A @ T_C = 25 °C - Supports sustained load current in heatsink-mounted TO-220 configurations.
E_AS	220 mJ - Single-pulse avalanche energy rating confirms ruggedness under unclamped inductive turn-off stress.
t_rr	245 ns @ I_SD = 3.8 A, di/dt = 100 A/µs, T_j = 150 °C - Fast body diode recovery reduces switching loss and EMI in bridge topologies.
Q_g	15–21 nC @ V_DD = 400 V, I_D = 3.8 A - Low total gate charge allows efficient driving with moderate-strength gate drivers.
dv/dt	4.5 V/ns - High inherent noise immunity prevents spurious turn-on during fast transient events.

Pinout & Package

STP4NB50 is housed in a through-hole TO-220 package with isolated tab (pin 2), offering 1.56 °C/W junction-to-case thermal resistance and 62.5 °C/W junction-to-ambient rating under standard PCB mounting conditions.

Pin/Terminal	Circuit Role	Design Meaning
1 (Gate)	Control electrode	Receives gate drive signal; threshold voltage 2–4 V enables TTL/CMOS-compatible driving.
2 (Drain)	High-side power terminal	Connected to high-voltage rail; electrically isolated metal tab supports heatsinking and high-voltage clearance.
3 (Source)	Power return / reference node	Serves as common return path for load current and gate driver ground; defines local ground reference for control loop.

Key Features

Feature	Design Value
100% avalanche tested	Guarantees minimum 220 mJ single-pulse avalanche energy, enabling reliable operation in inductive switching without derating.
Extremely high dv/dt capability	4.5 V/ns rating suppresses false triggering during fast voltage transients in high-noise industrial environments.
Minimized gate charge	Total Q_g of 15–21 nC reduces driver power demand and switching transition time, lowering overall system losses.
Low intrinsic capacitances	C_iss = 400 pF, C_oss = 62 pF, C_rss = 7.5 pF - Minimizes capacitive coupling and improves high-frequency efficiency.
Very low R_DS(on) per die area	2.5 Ω @ 10 V reflects optimized PowerMesh™ layout, reducing conduction loss and thermal footprint vs. conventional planar MOSFETs.

Applications

Welding Inverter Primary Switch

UPS DC-AC Inverter Stage

Use Scenario: High-frequency (20–50 kHz) hard-switched primary-side switch in IGBT-assisted or all-MOSFET welding inverters handling 3–5 kVA output.

IC Role / Device Role / Timing Role: Main power switch controlling energy transfer from DC bus to high-frequency transformer primary winding.

Use Value: 500 V rating and 220 mJ avalanche energy allow safe operation under reflected inductive spikes; 245 ns t_rr limits cross-conduction loss in full-bridge configurations.

Use Scenario: Output stage switch in online double-conversion UPS systems converting 380–400 V DC bus to 230 V AC via H-bridge or push-pull topology.

IC Role / Device Role / Timing Role: High-voltage leg switch sustaining bus voltage while delivering sinusoidal output current with PWM modulation.

Use Value: 4.5 V/ns dv/dt immunity prevents false turn-on during rapid bus voltage transitions; low C_oss (62 pF) reduces dead-time-related distortion.

Industrial SMPS Primary Switch

Motor Drive Half-Bridge Leg

Use Scenario: 100–300 W off-line flyback or forward converter operating at 65–130 kHz in factory automation power supplies.

IC Role / Device Role / Timing Role: Primary-side switching element regulating energy delivery into transformer, driven by UC384x or similar controller.

Use Value: 2.5 Ω R_DS(on) minimizes conduction loss at 3.8 A peak; 1.56 °C/W R_th(j-c) enables compact heatsink design in enclosed enclosures.

Use Scenario: Upper-leg switch in 400 V DC bus half-bridge driving 0.5–2 kW induction motors in HVAC blowers or conveyor drives.

IC Role / Device Role / Timing Role: High-side power switch controlled via isolated gate driver, subject to shoot-through and commutation stress.

Use Value: Body diode Q_rr = 980 nC and I_RRM = 9 A support freewheeling during PWM dead time without external diodes; avalanche rating handles motor back-EMF transients.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage N-channel MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP5NB50	Higher I_D = 4.4 A, same V_DSS = 500 V, R_DS(on) = 2.2 Ω typ, Q_g = 22 nC	Supports higher continuous current but requires larger heatsink due to increased power dissipation at same R_DS(on).	Select when >3.8 A continuous current or lower on-resistance is required; verify gate drive strength for +30% Q_g.
FQP4N50	Same V_DSS = 500 V, R_DS(on) = 2.7 Ω typ, I_D = 4.0 A, Q_g = 18 nC, TO-220 package	Lower avalanche rating (E_AS not specified), no guaranteed dv/dt or 100% avalanche test data.	Acceptable for non-critical SMPS where cost is prioritized over ruggedness; avoid in welding or motor drive with unclamped inductance.

Compared with STP5NB50 and FQP4N50, STP4NB50 offers the best balance of verified avalanche robustness (220 mJ), industry-leading dv/dt immunity (4.5 V/ns), and low gate charge-making it preferred for mission-critical industrial switching where reliability under transient stress is mandatory.

Availability

STP4NB50 is available at Aetrix Electronics and suitable for welding inverters, UPS DC-AC stages, and industrial SMPS requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STP4NB50 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs and discrete power devices for automotive, industrial, and consumer markets.

The PowerMesh™ MOSFET product line targets high-reliability industrial power conversion, emphasizing avalanche ruggedness, high dv/dt immunity, and low switching losses in 400–650 V applications.

FAQ

Is STP4NB50 suitable for use in avalanche mode?

Yes. STP4NB50 is 100% avalanche tested with a guaranteed single-pulse avalanche energy rating of 220 mJ at T_j = 25 °C. This makes it suitable for unclamped inductive switching applications such as relay driving, solenoid control, and welding inverters where energy must be safely absorbed within the MOSFET.

What is the maximum gate-source voltage rating?

The absolute maximum gate-source voltage for STP4NB50 is ±30 V. Operation beyond this range risks permanent gate oxide damage. For reliable switching, gate drive should be limited to 10–15 V for turn-on and –5 to 0 V for turn-off, with transient overshoots clamped below ±20 V using Zener protection.

Does STP4NB50 have an integrated body diode?

Yes. STP4NB50 includes a monolithic source-drain body diode with forward voltage V_SD = 1.6 V at I_SD = 3.8 A and reverse recovery characteristics t_rr = 245 ns and Q_rr = 980 nC at T_j = 150 °C. This diode is fully characterized and rated for use in synchronous rectification and freewheeling paths.

Can STP4NB50 replace STP4NK50Z in existing designs?

No. STP4NK50Z uses ST's newer MDmesh™ Z technology with lower R_DS(on) (1.8 Ω) and higher speed, but different gate charge profile and avalanche behavior. STP4NB50 has higher R_DS(on) (2.5 Ω), lower Q_g, and distinct SOA curves. Direct replacement requires revalidation of thermal, switching, and avalanche margins.

STP4NB50 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: PowerMESH™

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 500 V

Current - Continuous Drain (Id) @ 25°C:: 3.8A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 10V

Rds On (Max) @ Id, Vgs:: 2.8Ohm @ 1.9A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 21 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 400 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 80W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

STP4NB50 FAQ

1.How can I place an order for STP4NB50 through Aetrix?

Please submit a Request for Quotation (RFQ) for STP4NB50 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for STP4NB50 reliable?

The price and inventory of STP4NB50 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STP4NB50 is usually 5 days.

3.What payment methods are accepted for STP4NB50?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STP4NB50 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STP4NB50?

STP4NB50 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STP4NB50 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for STP4NB50?

For technical support, including STP4NB50 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STP4NB50 requirements.

6.How does Aetrix verify that STP4NB50 is sourced from the original manufacturer or authorized distributors?

All STP4NB50 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STP4NB50 meets industry standards.

7.What is the process for return or replacement of STP4NB50?

All STP4NB50 units undergo pre-shipment inspection (PSI). If there is an issue with STP4NB50, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The STP4NB50 part is unused and in its original packaging.

Return procedure for STP4NB50:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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