onsemi FJE5304DTU

Overview

FJE5304DTU from ON Semiconductor is an NPN triple-diffused planar silicon power transistor in TO-126 package, rated for 400 V V_CEO, 4 A I_C (DC), and 30 W P_C at T_C = 25°C, with built-in free-wheeling diode and optimized for high-voltage, high-speed switching in electronic ballasts.

For engineers reviewing the FJE5304DTU datasheet, pinout, applications, or equivalent options, key selection criteria include its 400 V collector-emitter breakdown voltage, 0.6 μs storage time under inductive load, 2.5 V internal diode forward drop at 2 A, and TO-126 thermal resistance of 4.17°C/W junction-to-case.

Technical Context

The FJE5304DTU employs a triple-diffused planar structure to achieve wide safe operating area (SOA) and low saturation voltage-V_CE(sat) = 1.5 V at I_C = 2.5 A, I_B = 0.5 A-enabling robust operation in repetitive inductive switching circuits. Its integrated anti-parallel diode eliminates external flyback diode requirements in half-bridge and chopper topologies.

Designed for electronic ballast control, the device delivers fast switching performance: t_stg = 0.6 μs and t_f = 0.1 μs under V_CC = 200 V inductive load conditions. DC current gain h_FE ranges from 8 to 40 depending on operating point, supporting stable base-driven switching across 10 mA–2 A collector current range.

Key Specifications

Pinout & Package

Package: TO-126 3L, thermally enhanced plastic case with metal tab for heatsink mounting. Pin 1 = Emitter, Pin 2 = Collector (tab-connected), Pin 3 = Base - confirmed per Fairchild FJE5304D Rev. 2 mechanical drawing and absolute maximum ratings table.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BU508AF and MJD122G, the FJE5304DTU uniquely combines 400 V rating, integrated diode, and TO-126 thermal performance-making it a purpose-fit solution for cost-sensitive, thermally constrained electronic ballasts where diode integration directly reduces bill-of-materials cost and layout area.

Availability

FJE5304DTU is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, LED driver chopper stages, induction heating half-bridges, and DC motor flyback protection requiring stable component supply despite product discontinuation status.

Supply support for FJE5304DTU 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

ON Semiconductor (formerly Fairchild Semiconductor) is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The FJE5304DTU belongs to ON Semiconductor's legacy high-voltage bipolar transistor product line, engineered specifically for electronic ballast and high-frequency switching applications demanding ruggedness, integrated diode functionality, and predictable SOA behavior.

FAQ

Is the FJE5304DTU still in active production?

No, the FJE5304DTU is officially discontinued per ON Semiconductor documentation. However, Aetrix Electronics maintains limited legacy inventory and supports continuity programs including last-time buy coordination and cross-reference guidance for functional alternatives. Customers should verify current stock status and lead times directly with Aetrix prior to design-in.

What is the pin configuration of the FJE5304DTU in TO-126 package?

The FJE5304DTU uses standard TO-126 pinout: Pin 1 = Emitter, Pin 2 = Collector (electrically connected to metal tab), Pin 3 = Base. This configuration is confirmed in the Fairchild FJE5304D Rev. 2 datasheet mechanical drawing and absolute maximum ratings table. Mounting requires electrical isolation of the collector tab unless circuit topology mandates common-collector grounding.

Does the FJE5304DTU have an integrated diode, and what are its specifications?

Yes, the FJE5304DTU includes a built-in freewheeling diode. Its forward voltage drop V_f is specified as 2.5 V at I_F = 2 A, enabling efficient energy recirculation during inductive turn-off events. This diode eliminates the need for an external flyback diode in chopper and half-bridge configurations, reducing component count and PCB area in FJE5304DTU-based designs.

What thermal performance can be expected from the FJE5304DTU?

The FJE5304DTU has a junction-to-case thermal resistance R_θJC of 4.17°C/W and maximum collector dissipation P_C of 30 W at T_C = 25°C. When mounted to a heatsink with ≤1.5°C/W total thermal resistance (including interface), the device sustains full-rated current at case temperatures up to 100°C-critical for sealed-ballast thermal environments where airflow is restricted.

Can the FJE5304DTU replace the FJE5304D in existing designs?

Yes, the FJE5304DTU is functionally identical to the FJE5304D except for packaging: FJE5304D ships in bulk while FJE5304DTU is supplied in rail format. Both share identical electrical specifications, pinout, thermal characteristics, and TO-126 package dimensions. No PCB or schematic changes are required when substituting FJE5304DTU for FJE5304D in production or repair scenarios.