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

STMicroelectronics STB40N20

Name: STB40N20
Brand: STMicroelectronics
SKU: STB40N20
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STB40N20

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Datasheet:: STB40N20.pdf

Description:: MOSFET N-CH 200V 40A D2PAK

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Product details

Overview

STB40N20 from STMicroelectronics is an N-channel enhancement-mode power MOSFET in D2PAK package, rated for 200V drain-source voltage, <0.045Ω R_DS(on) at V_GS = 10V and 20A, 40A continuous drain current at T_C = 25°C, and 160W total power dissipation - optimized as primary switch in high-efficiency isolated DC-DC converters.

For engineers reviewing the STB40N20 datasheet, STB40N20 pinout, STB40N20 application, or STB40N20 equivalent, key selection factors include gate charge (75nC), low output capacitance (C_oss = 510pF), avalanche ruggedness (E_AS = 230mJ), thermal resistance (R_thj-case = 3.1°C/W), and D2PAK surface-mount compatibility for high-power density board layouts.

Technical Context

This STripFET™ II device uses a trench-gate process to minimize gate charge (Q_g = 75nC) and intrinsic capacitances (C_iss = 2500pF, C_oss = 510pF), enabling fast switching with reduced driver loss in hard-switched topologies. Its 100% avalanche-tested construction ensures robustness under unclamped inductive load conditions.

The MOSFET features a low-threshold gate drive (V_GS(th) = 2–4V), operates up to T_j = 150°C, and delivers stable R_DS(on) performance across temperature (typ. +0.5%/°C). The integrated source-drain diode supports synchronous rectification with t_rr = 192ns (T_j = 25°C) and Q_rr = 922nC.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	200V - Withstands 200V drain-to-source blocking voltage before avalanche onset; suitable for 100–120VAC input-derived 375V bus or 48V/60V telecom systems with margin.
R_DS(on)	<0.045Ω @ V_GS=10V, I_D=20A - Enables ≤3.6W conduction loss at 20A, critical for high-current primary-side switching in 100–500W SMPS.
Q_g	75nC - Low gate charge reduces driver power and enables use of smaller gate drivers in high-frequency (≥100kHz) flyback or LLC resonant converters.
E_AS	230mJ - Single-pulse avalanche energy rating allows reliable operation during transient overvoltage events without external snubbers in offline applications.
R_thj-case	3.1°C/W - Junction-to-case thermal resistance enables 160W power handling with moderate heatsinking; D2PAK footprint supports direct PCB copper pour thermal transfer.
t_r/t_f	44ns/22ns - Fast rise/fall times minimize switching losses in hard-switched topologies; requires careful gate loop layout to suppress ringing.

Pinout & Package

D2PAK (TO-263) package: surface-mount, single-row 3-pin outline with exposed drain pad for thermal and electrical connection. Pin 1 = Gate, Pin 2 = Drain (tab), Pin 3 = Source.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	Gate	Control terminal; accepts 10V logic-level drive; low input capacitance (C_iss = 2500pF) eases driver design.
Pin 2	Drain	Main high-side power terminal; electrically and thermally connected to exposed metal tab; must be isolated from heatsink unless referenced to same potential.
Pin 3	Source	Power return path and reference for gate drive; ties to power ground plane; carries full load current and reverse recovery current of body diode.

Key Features

Feature	Design Value
STripFET™ II process	Enables ultra-low gate charge (75nC) and figure-of-merit R_DS(on) × Q_g = 3.39Ω·nC - directly improves efficiency in high-frequency switching.
100% avalanche tested	Guarantees minimum 40A repetitive avalanche current and 230mJ single-pulse energy - eliminates need for derating in unclamped inductive designs.
Low C_oss & C_rss	C_oss = 510pF, C_rss = 78pF - reduces capacitive turn-off loss and improves zero-voltage switching (ZVS) capability in resonant converters.
ECOPACK® compliance	Lead-free second-level interconnect per JEDEC JESD97; RoHS-compliant packaging with marked environmental category on label and inner box.

Applications

Server PSU Primary Switch

Industrial DC-DC Converter

Use Scenario: Primary-side switch in 375V-input, 12V/40A isolated forward converter for rack-mounted servers.

IC Role / Device Role / Timing Role: High-side main switch operating at 100–200kHz with synchronous rectification on secondary side.

Use Value: Low Q_g and R_DS(on) reduce combined conduction and switching losses to <4.2W at full load, enabling >93% efficiency at 500W output.

Use Scenario: Main switching element in 48V-to-12V isolated half-bridge DC-DC module for factory automation PLCs.

IC Role / Device Role / Timing Role: Hard-switched primary FET with active clamp snubber; handles 40A peak primary current at 150kHz.

Use Value: Avalanche ruggedness (E_AS = 230mJ) tolerates clamp circuit transients; D2PAK thermal performance sustains 160W dissipation with 2oz copper heatsink pad.

Telecom Rectifier Module

Renewable Energy Inverter Stage

Use Scenario: Primary switch in 380V bus telecom rectifier supplying 54V/30A to distributed power architecture.

IC Role / Device Role / Timing Role: Fixed-frequency PWM-controlled switch in phase-shifted full-bridge topology.

Use Value: Low C_oss minimizes dead-time losses; fast t_r/t_f (44ns/22ns) enables precise timing control for ZVS transition at light loads.

Use Scenario: High-side switch in bidirectional DC-DC stage interfacing battery bank (48–60V) with 300–400V PV string in hybrid solar microinverter.

IC Role / Device Role / Timing Role: Unidirectional power flow switch in non-isolated buck-boost stage operating at variable frequency up to 250kHz.

Use Value: Body diode t_rr = 192ns and Q_rr = 922nC enable efficient freewheeling with minimal voltage overshoot during commutation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 200V power MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP40N20	Same silicon die, TO-220 through-hole package; R_thj-case = 0.78°C/W vs. 3.1°C/W; higher P_tot = 160W at T_C = 25°C.	Preferred where mechanical mounting stability and forced-air cooling are available; unsuitable for dense SMT layouts.	Select STP40N20 when board space permits through-hole assembly and thermal interface to large heatsink is assured.
IRFP460	200V, 20A, R_DS(on) = 0.27Ω, Q_g = 140nC - significantly higher conduction and switching loss; no avalanche rating specified.	Limited to lower-frequency (<50kHz), lower-efficiency designs; requires external avalanche protection in unclamped circuits.	Use only as legacy drop-in replacement where efficiency and ruggedness are secondary to cost and availability.

Compared with STP40N20, STB40N20 trades higher thermal resistance for SMT manufacturability and board-level power density; versus IRFP460, it delivers 6× lower R_DS(on), 2× lower Q_g, and guaranteed avalanche capability - making it superior for modern high-frequency, high-reliability power conversion.

Availability

STB40N20 is available at Aetrix Electronics and suitable for server power supplies, industrial DC-DC modules, and telecom rectifier systems requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for STB40N20 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, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs, discrete devices, and MEMS sensors for automotive, industrial, and consumer markets.

The STripFET™ power MOSFET product line targets high-efficiency, high-reliability power conversion - specifically engineered for primary-side switching in isolated DC-DC, AC-DC, and renewable energy systems demanding low Q_g, low R_DS(on), and robust avalanche performance.

FAQ

What is the maximum continuous drain current for STB40N20 at 100°C case temperature?

The maximum continuous drain current is 25A at T_C = 100°C, as specified in Table 1 of the datasheet. This derating reflects thermal limits of the D2PAK package (R_thj-case = 3.1°C/W); operation above this current requires active cooling or pulse-width limitation to maintain T_j ≤ 150°C.

Does STB40N20 support logic-level gate drive?

No - STB40N20 has a gate threshold voltage range of 2–4V but requires V_GS = 10V to achieve its specified R_DS(on) < 0.045Ω. Driving it with 5V logic will result in significantly higher on-resistance (>0.15Ω) and excessive conduction loss; a dedicated 10–15V gate driver is mandatory.

Can STB40N20 be used in synchronous rectification configurations?

Yes - its integrated body diode has t_rr = 192ns and Q_rr = 922nC at 25°C, enabling controlled commutation in synchronous rectifier stages. However, external Schottky or MOSFET-based synchronous rectifiers are preferred for lowest loss; STB40N20's diode is intended for freewheeling, not primary rectification.

Is STB40N20 suitable for automotive applications?

No - STB40N20 is not qualified to AEC-Q101 and lacks automotive-grade screening, temperature cycling validation, or guaranteed operation beyond 150°C junction. It is intended for industrial, telecom, and computing power supplies; automotive designs require explicitly qualified parts such as STL40N20LH6.

STB40N20 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: STripFET™

Package/Case:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 200 V

Current - Continuous Drain (Id) @ 25°C:: 40A (Tc)

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

Rds On (Max) @ Id, Vgs:: 45mOhm @ 20A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 75 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 2500 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 160W (Tc)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: D2PAK

STB40N20 FAQ

1.How can I place an order for STB40N20 through Aetrix?

Please submit a Request for Quotation (RFQ) for STB40N20 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 STB40N20 reliable?

The price and inventory of STB40N20 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STB40N20 is usually 5 days.

3.What payment methods are accepted for STB40N20?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STB40N20 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STB40N20?

STB40N20 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STB40N20 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 STB40N20?

For technical support, including STB40N20 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STB40N20 requirements.

6.How does Aetrix verify that STB40N20 is sourced from the original manufacturer or authorized distributors?

All STB40N20 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 STB40N20 meets industry standards.

7.What is the process for return or replacement of STB40N20?

All STB40N20 units undergo pre-shipment inspection (PSI). If there is an issue with STB40N20, 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 STB40N20 part is unused and in its original packaging.

Return procedure for STB40N20:

1.Submit a request within 90 days.

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

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