Alpha & Omega Semiconductor Inc. AOT14N50

Overview

AOT14N50 from Alpha & Omega Semiconductor is a 500 V, 14 A N-channel enhancement-mode MOSFET in TO-220 package, featuring 0.42 Ω R_DS(on) at V_GS = 10 V, 100% avalanche-rated operation, and designed for high-voltage DC-DC converters, offline SMPS, and motor control circuits.

For engineers reviewing the AOT14N50 datasheet, pinout, applications, or equivalent options, key selection criteria include its 500 V blocking voltage, 14 A continuous drain current, low gate charge (Q_g = 32 nC), rugged avalanche capability, and TO-220 thermal performance under forced-air convection.

Technical Context

The AOT14N50 employs planar stripe DMOS technology to achieve stable high-voltage operation with tight parameter distribution. Its gate threshold voltage (V_GS(th)) ranges from 2.0 V to 4.0 V, and it supports standard logic-level gate drive with 10 V V_GS for full enhancement.

Thermal design relies on the TO-220 package's exposed drain tab for direct heatsink mounting. The device meets JEDEC JESD47 reliability standards and is rated for 100% UIS (unclamped inductive switching) testing at 25 °C case temperature.

Key Specifications

Pinout & Package

TO-220 package with drain-connected tab (pin 2), source (pin 1), and gate (pin 3); tab electrically connected to drain for direct heatsink mounting and thermal path optimization.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP14NK50ZFP and FQP14N50, the AOT14N50 delivers lower conduction loss and verified avalanche ruggedness-critical for unclamped inductive loads-while maintaining identical TO-220 footprint and gate drive compatibility.

Availability

AOT14N50 is available at Aetrix Electronics and suitable for industrial motor drives, offline switch-mode power supplies, and DC-DC converters requiring stable component supply across extended production cycles.

Supply support for AOT14N50 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 ICs for computing, consumer, and industrial markets.

The AOT14N50 belongs to AOS's high-voltage discrete MOSFET product line, engineered for rugged, high-reliability switching in 400–500 V DC bus systems with emphasis on avalanche survivability and thermal stability.

FAQ

What is the maximum junction temperature for the AOT14N50?

The AOT14N50 has a maximum rated junction temperature (T_J) of 150 °C per its official datasheet. Operation above this limit risks permanent parametric shift or catastrophic failure. Derating curves specify that continuous I_D must be reduced linearly above 25 °C case temperature, and thermal design must ensure T_J remains ≤150 °C under worst-case ambient and power dissipation conditions. The AOT14N50 datasheet provides detailed thermal resistance values (R_θJC = 1.2 °C/W) to support this calculation.

Does the AOT14N50 support logic-level gate drive?

The AOT14N50 is not a logic-level MOSFET; its gate threshold voltage (V_GS(th)) is specified from 2.0 V to 4.0 V, but full enhancement requires V_GS ≥ 10 V to achieve rated R_DS(on) = 0.42 Ω. Driving the AOT14N50 with only 5 V logic signals results in significantly higher on-resistance (>1.5 Ω) and excessive conduction loss. A dedicated gate driver or level-shifting circuit is required to deliver 10–15 V to the gate of the AOT14N50 in practical applications.

Is the AOT14N50 pin-compatible with other TO-220 N-channel MOSFETs?

Yes-the AOT14N50 uses standard TO-220AB mechanical outline with drain-connected tab (pin 2), source (pin 1), and gate (pin 3), matching industry-standard pinout. This allows direct PCB footprint reuse with devices like STP14NK50ZFP and FQP14N50. However, electrical differences-including R_DS(on), Q_g, and avalanche rating-require validation of gate drive strength, thermal margins, and fault robustness before substitution. The AOT14N50's pinout is confirmed in Alpha & Omega's PO-00015 package drawing.

What is the typical gate charge (Q_g) of the AOT14N50 and how does it affect switching performance?

The AOT14N50 has a typical total gate charge (Q_g) of 32 nC at V_GS = 10 V, measured from 0 V to 10 V. This value directly determines required gate driver peak current and switching transition times: for a 20 ns rise time, ~1.6 A peak drive current is needed. Higher Q_g increases driver power loss and slows turn-on, impacting efficiency in high-frequency SMPS. The AOT14N50's Q_g is documented in its official datasheet and validated via production test data.

Can the AOT14N50 be used in avalanche mode intentionally?

Yes-the AOT14N50 is 100% tested for single-pulse unclamped inductive switching (UIS) with E_AS = 390 mJ at T_C = 25 °C. This confirms its ability to absorb inductive energy safely during transient overloads, such as relay coil de-energization or motor phase commutation. However, repetitive avalanche operation is not characterized or guaranteed. For reliable long-term use, the AOT14N50 should be operated within SOA limits, and avalanche should remain an emergency fail-safe-not a design feature. All AOT14N50 units undergo UIS screening per AOS quality protocol.