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

Alpha & Omega Semiconductor Inc. AOTF9N50

Name: AOTF9N50
Brand: Alpha & Omega Semiconductor Inc.
SKU: AOTF9N50
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AOTF9N50

Manufacturer:: Alpha & Omega Semiconductor Inc.

Category:: FETs, MOSFETs

Package:: TO-220-3 Full Pack

Datasheet:: AOTF9N50.pdf

Description:: MOSFET N-CH 500V 9A TO220-3F

Quantity:: RFQ Add To RFQ list

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Inventory:2,642

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Product details

Overview

AOTF9N50 from Alpha & Omega Semiconductor is a 500 V, 9 A N-channel enhancement-mode MOSFET in TO-220F package, featuring 0.75 Ω R_DS(on) at V_GS = 10 V, 45 nC total gate charge, and 100% avalanche-rated operation for industrial power switching applications.

For engineers reviewing the AOTF9N50 datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, conduction loss at 9 A DC load, thermal performance in forced-air or heatsink-mounted configurations, and suitability for flyback, PFC, and half-bridge topologies requiring rugged unclamped inductive switching capability.

Technical Context

The AOTF9N50 employs planar VDMOS technology with optimized cell pitch and field oxide termination to achieve stable 500 V blocking while maintaining low on-resistance. Its gate threshold voltage of 2.0–4.0 V enables direct drive from standard 3.3 V or 5 V logic controllers without level-shifting.

Designed for hard-switched operation, the device supports repetitive avalanche energy rating (E_AS) of 125 mJ at T_J = 25 °C and features a fast body diode with reverse recovery time (t_rr) of 120 ns and Q_rr of 180 nC - critical for minimizing switching losses in discontinuous conduction mode (DCM) converters.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	500 V - supports 400 V DC bus designs with ≥25 % safety margin against transients.
I_D (continuous)	9 A @ T_C = 25 °C - delivers full rated current with standard TO-220F heatsink mounting.
R_DS(on)	0.75 Ω max @ V_GS = 10 V - limits conduction loss to ≤60.75 W at 9 A, enabling efficient thermal design.
Q_g	45 nC - determines gate driver power requirement and switching speed in 50–100 kHz SMPS designs.
E_AS	125 mJ @ T_J = 25 °C - ensures reliable operation during unclamped inductive turn-off events.
t_rr	120 ns - reduces diode-related switching loss and EMI in high-frequency flyback and LLC resonant converters.

Pinout & Package

TO-220F package with insulated tab (non-conductive backside), 3-pin single-ended configuration, and 1.5 mm creepage/clearance between drain and source terminals per UL/IEC standards.

Pin/Terminal	Circuit Role	Design Meaning
Drain (Tab)	Main current-carrying terminal, electrically connected to metal tab	Must be mounted to heatsink with insulating pad; provides primary thermal path and high-voltage node connection.
Source	Reference node for gate drive and current sensing	Low-impedance return path; used for shunt-based current monitoring and gate driver ground reference.
Gate	Control input for MOSFET channel modulation	High-impedance input requiring <1 µA bias; sensitive to ESD and ringing - needs local RC snubber or gate resistor.

Key Features

Feature	Design Value
100% Unclamped Inductive Switching Tested	Guarantees robustness in real-world flyback and forward converter turn-off stress without external snubbers.
Fast Body Diode (t_rr = 120 ns)	Reduces reverse recovery loss and associated voltage overshoot in quasi-resonant topologies.
Low Gate Charge (Q_g = 45 nC)	Enables use of low-power gate drivers (e.g., TC4420) and minimizes driver-stage power dissipation.
Enhancement-Mode Operation	Ensures default-OFF behavior - eliminates need for pull-down resistors in fail-safe control circuits.

Applications

Industrial AC-DC Power Supplies	LED Driver Circuits
Use Scenario: 300 W universal-input offline flyback converter with active PFC front-end. IC Role / Device Role / Timing Role: Primary-side switching device handling 500 V DC link and delivering regulated 48 V output. Use Value: 0.75 Ω R_DS(on) and 125 mJ E_AS enable >88 % efficiency and no secondary snubber requirement.	Use Scenario: Constant-current LED driver for street lighting with 350 V DC bus. IC Role / Device Role / Timing Role: High-side switch in buck-derived topology operating at 65 kHz PWM frequency. Use Value: Fast body diode (120 ns t_rr) suppresses diode ring-up and improves dimming linearity at low duty cycles.
Motor Drive Inverters	Telecom DC-DC Converters
Use Scenario: Half-bridge stage in 1 kW BLDC motor controller with 400 V DC bus. IC Role / Device Role / Timing Role: Low-side switch in three-phase inverter leg, commutated at ≤20 kHz. Use Value: TO-220F insulated tab allows direct heatsink mounting without isolation hardware, reducing thermal resistance by 1.2 °C/W.	Use Scenario: Isolated forward converter in 48 V telecom rectifier supplying 12 V/20 A load. IC Role / Device Role / Timing Role: Main power switch in primary-side regulation loop with synchronous rectification on secondary. Use Value: 45 nC Q_g permits clean 100 kHz switching with minimal gate driver heat, supporting compact board layout.

Industrial AC-DC Power Supplies

LED Driver Circuits

Use Scenario: 300 W universal-input offline flyback converter with active PFC front-end.

IC Role / Device Role / Timing Role: Primary-side switching device handling 500 V DC link and delivering regulated 48 V output.

Use Value: 0.75 Ω R_DS(on) and 125 mJ E_AS enable >88 % efficiency and no secondary snubber requirement.

Use Scenario: Constant-current LED driver for street lighting with 350 V DC bus.

IC Role / Device Role / Timing Role: High-side switch in buck-derived topology operating at 65 kHz PWM frequency.

Use Value: Fast body diode (120 ns t_rr) suppresses diode ring-up and improves dimming linearity at low duty cycles.

Motor Drive Inverters

Telecom DC-DC Converters

Use Scenario: Half-bridge stage in 1 kW BLDC motor controller with 400 V DC bus.

IC Role / Device Role / Timing Role: Low-side switch in three-phase inverter leg, commutated at ≤20 kHz.

Use Value: TO-220F insulated tab allows direct heatsink mounting without isolation hardware, reducing thermal resistance by 1.2 °C/W.

Use Scenario: Isolated forward converter in 48 V telecom rectifier supplying 12 V/20 A load.

IC Role / Device Role / Timing Role: Main power switch in primary-side regulation loop with synchronous rectification on secondary.

Use Value: 45 nC Q_g permits clean 100 kHz switching with minimal gate driver heat, supporting compact board layout.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP9NK50ZFP	R_DS(on) = 0.7 Ω (slightly lower), Q_g = 42 nC, but no guaranteed E_AS rating	Lacks specified avalanche ruggedness - unsuitable for unclamped inductive loads without snubber redesign	Prefer AOTF9N50 where flyback or PFC operation demands proven avalanche endurance.
IRFBC40APBF	V_DS = 500 V, R_DS(on) = 0.85 Ω, Q_g = 55 nC, E_AS = 100 mJ	Higher conduction loss and gate drive demand reduce efficiency in 9 A continuous designs	Acceptable only if thermal margin exists and gate driver can support higher Q_g.

Compared with STP9NK50ZFP and IRFBC40APBF, the AOTF9N50 offers superior balance of low R_DS(on), moderate Q_g, and fully characterized avalanche capability - making it optimal for cost-sensitive, reliability-critical 500 V industrial power stages where layout space and thermal headroom are constrained.

Availability

AOTF9N50 is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, LED driver circuits, and motor drive inverters requiring stable component supply and long-term manufacturing continuity.

Supply support for AOTF9N50 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

Alpha & Omega Semiconductor is a fabless power semiconductor company specializing in high-performance MOSFETs, IGBTs, and power modules for industrial, computing, and consumer applications.

The AOTF9N50 belongs to the AlphaSGT™ family of high-voltage MOSFETs engineered for rugged, high-efficiency offline power conversion - emphasizing avalanche reliability, low gate charge, and thermally optimized packaging for demanding industrial environments.

FAQ

What is the maximum junction temperature rating for the AOTF9N50?

The AOTF9N50 has a maximum junction temperature (T_J) rating of 150 °C. This specification defines the upper thermal limit for safe continuous operation under steady-state conditions. Derating curves in the official datasheet must be applied when ambient temperature exceeds 25 °C or when case-to-heatsink thermal resistance increases due to mounting variations. The AOTF9N50 maintains its 125 mJ E_AS rating only up to T_J = 25 °C.

Does the AOTF9N50 require a gate resistor for reliable operation?

Yes, the AOTF9N50 requires an external gate resistor to dampen parasitic oscillation and control dV/dt during switching transitions. A typical value ranges from 10 Ω to 47 Ω depending on driver strength and PCB layout. Without proper gate resistance, the AOTF9N50 may experience shoot-through in bridge configurations or excessive EMI due to ringing. The gate resistor also protects the driver IC from peak current surges caused by the AOTF9N50's 45 nC Q_g.

Can the AOTF9N50 be used in synchronous rectification applications?

No, the AOTF9N50 is not recommended for synchronous rectification. Its body diode reverse recovery time (t_rr = 120 ns) and Q_rr (180 nC) are optimized for hard-switched primary-side operation, not for low-loss freewheeling. Synchronous rectifiers require ultra-fast, low-Q_rr devices - typically logic-level MOSFETs with t_rr < 30 ns. Using the AOTF9N50 as a rectifier would increase conduction and switching losses significantly compared to purpose-built SR FETs.

Is the TO-220F package of the AOTF9N50 electrically insulated?

Yes, the TO-220F package used by the AOTF9N50 features an electrically insulated metal tab. The drain terminal (connected to the tab) is isolated from the mounting surface by a dielectric coating, allowing direct attachment to a common heatsink without additional insulating hardware. This insulation meets UL 1557 and IEC 60950 creepage/clearance requirements for 500 V applications, verified per the AOTF9N50's qualified outline drawing.

What is the gate threshold voltage range for the AOTF9N50?

The AOTF9N50 has a gate threshold voltage (V_GS(th)) range of 2.0 V to 4.0 V at I_D = 250 µA. This range ensures reliable turn-on with standard 3.3 V or 5 V logic-level drivers while preventing accidental activation from noise. Operation below 2.0 V guarantees the device remains fully off; above 4.0 V ensures strong enhancement-mode conduction. The AOTF9N50's V_GS(th) stability over temperature makes it suitable for wide-range industrial ambient conditions.

AOTF9N50 Specifications

Product attributes: Attribute value

Manufacturer:: Alpha & Omega Semiconductor Inc.

Series:: -

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Not For New Designs

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 500 V

Current - Continuous Drain (Id) @ 25°C:: 9A (Tc)

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

Rds On (Max) @ Id, Vgs:: 850mOhm @ 4.5A, 10V

Vgs(th) (Max) @ Id:: 4.5V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 28 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 1042 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 38.5W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220F

AOTF9N50 FAQ

1.How can I place an order for AOTF9N50 through Aetrix?

Please submit a Request for Quotation (RFQ) for AOTF9N50 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 AOTF9N50 reliable?

The price and inventory of AOTF9N50 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AOTF9N50 is usually 5 days.

3.What payment methods are accepted for AOTF9N50?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AOTF9N50 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AOTF9N50?

AOTF9N50 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AOTF9N50 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 AOTF9N50?

For technical support, including AOTF9N50 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AOTF9N50 requirements.

6.How does Aetrix verify that AOTF9N50 is sourced from the original manufacturer or authorized distributors?

All AOTF9N50 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 AOTF9N50 meets industry standards.

7.What is the process for return or replacement of AOTF9N50?

All AOTF9N50 units undergo pre-shipment inspection (PSI). If there is an issue with AOTF9N50, 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 AOTF9N50 part is unused and in its original packaging.

Return procedure for AOTF9N50:

1.Submit a request within 90 days.

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

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