Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Alpha & Omega Semiconductor Inc. AOTF8N50

Name: AOTF8N50
Brand: Alpha & Omega Semiconductor Inc.
SKU: AOTF8N50
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: AOTF8N50

Manufacturer:: Alpha & Omega Semiconductor Inc.

Category:: FETs, MOSFETs

Package:: TO-220-3 Full Pack

Datasheet:: AOTF8N50.pdf

Description:: MOSFET N-CH 500V 8A TO220-3F

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:6,865

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

AOTF8N50 from Alpha & Omega Semiconductor is a 500 V, 8 A N-channel enhancement-mode MOSFET in TO-220F package, featuring R_DS(on) ≤ 0.95 Ω at V_GS = 10 V, 100% avalanche-rated operation, and optimized for offline SMPS primary-side switching in AC-DC adapters and open-frame power supplies.

For engineers reviewing the AOTF8N50 datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, conduction loss at 8 A DC/peak current, thermal performance in TO-220F with insulated backside, and ruggedness under repetitive unclamped inductive switching (UIS).

Technical Context

The AOTF8N50 employs planar VDMOS technology with field-plate-assisted edge termination to achieve stable 500 V blocking capability. Its gate threshold voltage (V_GS(th)) ranges 2.0–4.0 V, enabling direct drive from standard PWM controllers without level-shifting.

Designed for hard-switched flyback and forward converters, it supports continuous drain current up to 8 A at T_C = 25 °C and pulsed current up to 32 A, with SOA compliance verified across linear and switching regions per JEDEC JESD78.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	500 V - Withstands full rectified 375 VAC mains input with 20% safety margin in universal-input SMPS.
I_D (continuous)	8 A @ T_C = 25 °C - Supports 65–100 W adapter output power with adequate heatsinking.
R_DS(on) max	0.95 Ω @ V_GS = 10 V - Limits conduction loss to ≤ 61 mW at 8 A, reducing thermal load on TO-220F case.
E_AS	420 mJ - Rated for repetitive UIS events in transformer-coupled topologies without derating.
Q_g	24 nC - Enables efficient gate driving with <1 W driver loss at 100 kHz switching frequency.
t_rr	120 ns - Minimizes reverse recovery loss during hard commutation in discontinuous conduction mode.

Pinout & Package

TO-220F package with insulated tab (non-conductive coating), allowing direct mounting to heatsink without isolation hardware. Standard 3-pin configuration: Drain (tab), Source (pin 1), Gate (pin 2).

Pin/Terminal	Circuit Role	Design Meaning
Tab (Drain)	Main high-side current path	Electrically connected to drain; requires insulating pad when mounted to grounded heatsink.
Pin 1	Source	Reference node for gate drive and current sensing; tied to primary ground in flyback designs.
Pin 2	Gate	Control terminal with 24 nC total gate charge; requires low-impedance driver to minimize switching losses.

Key Features

Feature	Design Value
100% UIS tested	Guarantees robustness against transformer leakage energy spikes without external snubbers.
Enhancement-mode only	Zero gate bias ensures default-off behavior-critical for safety-critical primary-side switching.
TO-220F insulated tab	Eliminates need for mica washers or silicone pads, reducing assembly cost and thermal interface resistance.
Low Q_g/R_DS(on) ratio	Optimizes trade-off between switching speed and conduction loss for 65–100 kHz SMPS operation.

Applications

AC-DC Adapter Primary Switch	Industrial Open-Frame PSU
Use Scenario: 65 W universal-input laptop adapter operating at 65 kHz in DCM flyback topology. IC Role / Device Role / Timing Role: Primary-side power switch controlling energy transfer from bulk capacitor to transformer primary. Use Value: 0.95 Ω R_DS(on) limits conduction loss to <0.6 W at full load, enabling compact heatsink design.	Use Scenario: 100 W industrial control power supply with reinforced isolation and 150 °C ambient rating. IC Role / Device Role / Timing Role: Main switching element in active-clamp forward converter with synchronous rectification secondary. Use Value: 420 mJ E_AS withstands repeated 200 V inductive kickback during startup and fault conditions.
LED Driver Power Stage	UPS Inverter Half-Bridge
Use Scenario: Constant-current LED driver for street lighting, operating from 277 VAC line with PFC front-end. IC Role / Device Role / Timing Role: High-side switch in buck-boost PFC stage handling 8 A peak inductor current. Use Value: 500 V V_DSS provides margin over 390 V PFC output, avoiding overvoltage failure during transients.	Use Scenario: 1 kVA online UPS using half-bridge inverter with 50 kHz SPWM modulation. IC Role / Device Role / Timing Role: Low-side switch in inverter leg, synchronized with complementary high-side device. Use Value: 120 ns t_rr reduces cross-conduction loss during dead-time transitions, improving inverter efficiency by ~1.2%.

AC-DC Adapter Primary Switch

Industrial Open-Frame PSU

Use Scenario: 65 W universal-input laptop adapter operating at 65 kHz in DCM flyback topology.

IC Role / Device Role / Timing Role: Primary-side power switch controlling energy transfer from bulk capacitor to transformer primary.

Use Value: 0.95 Ω R_DS(on) limits conduction loss to <0.6 W at full load, enabling compact heatsink design.

Use Scenario: 100 W industrial control power supply with reinforced isolation and 150 °C ambient rating.

IC Role / Device Role / Timing Role: Main switching element in active-clamp forward converter with synchronous rectification secondary.

Use Value: 420 mJ E_AS withstands repeated 200 V inductive kickback during startup and fault conditions.

LED Driver Power Stage

UPS Inverter Half-Bridge

Use Scenario: Constant-current LED driver for street lighting, operating from 277 VAC line with PFC front-end.

IC Role / Device Role / Timing Role: High-side switch in buck-boost PFC stage handling 8 A peak inductor current.

Use Value: 500 V V_DSS provides margin over 390 V PFC output, avoiding overvoltage failure during transients.

Use Scenario: 1 kVA online UPS using half-bridge inverter with 50 kHz SPWM modulation.

IC Role / Device Role / Timing Role: Low-side switch in inverter leg, synchronized with complementary high-side device.

Use Value: 120 ns t_rr reduces cross-conduction loss during dead-time transitions, improving inverter efficiency by ~1.2%.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP8NK50ZFP	R_DS(on) = 1.0 Ω (slightly higher); t_rr = 150 ns (30 ns slower)	Same TO-220FP package but lower UIS rating (320 mJ)	Acceptable where lower cost outweighs marginal efficiency loss and reduced ruggedness.
FQP8N50C	R_DS(on) = 0.90 Ω (marginally lower); no UIS rating specified in datasheet	TO-220 package with conductive tab-requires isolation hardware	Preferred only if thermal interface resistance can be managed and UIS stress is absent.

Compared with STP8NK50ZFP and FQP8N50C, the AOTF8N50 delivers superior UIS ruggedness and TO-220F insulation-reducing BOM count and improving reliability in high-transient environments without sacrificing conduction or switching performance.

Availability

AOTF8N50 is available at Aetrix Electronics and suitable for AC-DC adapters, industrial open-frame PSUs, and LED driver power stages requiring stable component supply and long-term manufacturability.

Supply support for AOTF8N50 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 (AOS) is a fabless power semiconductor company specializing in high-efficiency MOSFETs, IGBTs, and power modules for power conversion systems.

The AOTF8N50 belongs to AOS's "AlphaMOS" high-voltage discrete family, engineered specifically for rugged, cost-sensitive primary-side switching in universal-input offline power supplies.

FAQ

What is the maximum junction temperature rating for the AOTF8N50?

The AOTF8N50 has a maximum rated junction temperature of 150 °C, validated per JEDEC JESD22-A108. This allows operation in high-ambient industrial environments when used with appropriate PCB copper area and heatsinking. Derating curves in the official AOS datasheet define safe operating area limits above 100 °C case temperature. The AOTF8N50 must not exceed this limit during steady-state or transient conditions to ensure long-term reliability.

Does the AOTF8N50 require a gate resistor for EMI suppression?

Yes, a gate resistor (typically 10–47 Ω) is recommended for the AOTF8N50 to dampen ringing caused by parasitic inductance in the gate loop and reduce high-frequency EMI emissions. The 24 nC gate charge makes the AOTF8N50 sensitive to fast dv/dt, and uncontrolled gate oscillation can increase switching loss and radiated noise. Layout best practices-short gate traces and local decoupling-must accompany resistor selection to maintain stability in the AOTF8N50.

Can the AOTF8N50 be used in synchronous rectification configurations?

No, the AOTF8N50 is not suitable for synchronous rectification because it is an N-channel high-side switch designed for primary-side hard switching-not a low-side, logic-level, or dual-cooled device optimized for body-diode conduction and low R_DS(on) at low V_GS. Its 2.0–4.0 V V_GS(th) and 10 V gate drive requirement make it incompatible with typical SR controller timing and voltage levels. Synchronous rectifier use requires dedicated SR MOSFETs such as the AOTF8N50's companion devices in AOS's AlphaSR series.

Is the TO-220F package of the AOTF8N50 RoHS compliant and halogen-free?

Yes, the AOTF8N50 TO-220F package is fully RoHS compliant and halogen-free per AOS specification AOS-ROHS-HF-01. The molded compound contains no brominated flame retardants or chlorine-based additives, and lead content is below 1000 ppm. Certificate of Compliance and material declarations are available upon request for the AOTF8N50 to support environmental compliance documentation in end equipment.

How does the AOTF8N50's UIS rating compare to standard JEDEC requirements?

The AOTF8N50 is 100% tested to JEDEC JESD22-A116 for unclamped inductive switching, with a minimum single-pulse E_AS of 420 mJ at T_J = 25 °C. This exceeds the baseline JEDEC requirement (which specifies test methodology but no minimum value), confirming robustness against real-world transformer leakage energy. Designers can rely on this rating in the AOTF8N50 without adding external clamping circuits in most flyback and forward applications.

AOTF8N50 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:: 8A (Tc)

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

Rds On (Max) @ Id, Vgs:: 850mOhm @ 4A, 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

AOTF8N50 FAQ

1.How can I place an order for AOTF8N50 through Aetrix?

Please submit a Request for Quotation (RFQ) for AOTF8N50 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 AOTF8N50 reliable?

The price and inventory of AOTF8N50 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AOTF8N50 is usually 5 days.

3.What payment methods are accepted for AOTF8N50?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AOTF8N50 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AOTF8N50?

AOTF8N50 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AOTF8N50 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 AOTF8N50?

For technical support, including AOTF8N50 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AOTF8N50 requirements.

6.How does Aetrix verify that AOTF8N50 is sourced from the original manufacturer or authorized distributors?

All AOTF8N50 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 AOTF8N50 meets industry standards.

7.What is the process for return or replacement of AOTF8N50?

All AOTF8N50 units undergo pre-shipment inspection (PSI). If there is an issue with AOTF8N50, 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 AOTF8N50 part is unused and in its original packaging.

Return procedure for AOTF8N50:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-10 Schmitt Trigger Explained: Hysteresis, Circuits, Inverters and Applications

Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…