onsemi FJA4313RTU

Overview

FJA4313RTU from Fairchild Semiconductor is an NPN epitaxial silicon power transistor designed for high-fidelity audio output and general-purpose power amplification stages, featuring IC = 17 A DC collector current, VCEO = 250 V breakdown voltage, fT = 30 MHz gain-bandwidth product, PD = 130 W total dissipation at TC = 25°C, and TO-3P package with 3-pin terminal configuration.

For engineers reviewing the FJA4313RTU datasheet, pinout, applications, or equivalent options, key selection considerations include safe operating area (SOA) robustness, hFE linearity at IC = 1–7 A, VCE(sat) ≤ 3.0 V at IC = 8 A/IB = 0.8 A, thermal resistance RθJC = 0.96 °C/W, and complementarity to 2SA1962/FJA4213 in push-pull amplifier designs.

Technical Context

This device operates as a linear-mode bipolar junction transistor optimized for Class AB audio output stages and medium-frequency switching applications up to 30 MHz. Its wide SOA supports reliable operation under reactive loads and transient overcurrent conditions without secondary breakdown.

It delivers excellent gain linearity (hFE1 = 55–110, hFE2 = 35–60) across IC = 1–7 A, enabling low total harmonic distortion (THD) in high-fidelity amplifiers. The TO-3P metal package ensures low thermal resistance (0.96 °C/W) and mechanical stability for heatsink mounting.

Key Specifications

Pinout & Package

Package: TO-3P (metal can, isolated collector tab), dimensions 23.40 × 19.90 × 16.50 mm (L×W×H), with integral mounting hole (ø3.20 mm). Collector is electrically connected to the case tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SC5242RTU, FJA4313RTU offers identical performance and drop-in compatibility; versus MJE15030G, it provides +50 V breakdown margin, +15 MHz bandwidth, and -0.29 °C/W thermal advantage-critical for high-voltage, high-fidelity, or thermally constrained designs.

Availability

FJA4313RTU is available at Aetrix Electronics and suitable for high-fidelity audio amplifiers, industrial power regulators, and discrete RF driver stages requiring stable component supply, consistent hFE grading, and long-term thermal reliability.

Supply support for FJA4313RTU 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

Fairchild Semiconductor was a U.S.-based analog and power semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-reliability discrete transistors and power ICs.

FJA4313RTU belongs to Fairchild's FJA-series high-power audio transistor family, engineered specifically for low-distortion, thermally robust output stages in professional and consumer audio equipment.

FAQ

What is the pin configuration of the FJA4313RTU?

The FJA4313RTU uses a TO-3P package with three terminals: Pin 1 is Base, Pin 2 is Collector (electrically tied to the metal case tab), and Pin 3 is Emitter. This configuration is standardized across Fairchild's FJA and 2SC52xx series, enabling direct PCB footprint compatibility with 2SC5242RTU and FJA4213 in complementary designs.

Does the FJA4313RTU support complementary operation with a PNP transistor?

Yes, the FJA4313RTU is explicitly designed as the NPN complement to the PNP FJA4213 transistor. Both share matched hFE ranges, SOA curves, thermal resistance, and TO-3P packaging-enabling symmetrical push-pull amplifier stages with minimized crossover distortion and thermal tracking.

What is the maximum safe collector current for continuous operation of the FJA4313RTU?

The FJA4313RTU supports IC = 17 A DC collector current at TC = 25°C, but practical continuous current depends on heatsinking. With RθJC = 0.96 °C/W and TJ(max) = +150°C, sustained 10 A operation requires case temperature ≤ 80°C-achievable with a 0.5 °C/W heatsink and forced air cooling.

Is SPICE modeling supported for the FJA4313RTU?

Yes, Fairchild provided both thermal and electrical SPICE models for the FJA4313RTU, covering DC, AC, and transient behavior including junction temperature effects. These models are validated against measured hFE, VCE(sat), Cob, and SOA data in the official datasheet Rev. C and remain usable in modern simulators for amplifier stability and thermal analysis.

How does the FJA4313RTU differ from the FJP5200 in terms of package and power handling?

The FJA4313RTU uses a TO-3P package rated for 130 W at TC = 25°C and features VCEO = 250 V, while the FJP5200 uses a smaller TO-220 package rated for only 80 W and shares the same 250 V rating. The TO-3P's lower RθJC (0.96 vs ~2.5 °C/W for TO-220) makes FJA4313RTU superior for high-power, thermally demanding applications where heatsink space permits.