onsemi 2N3415

Overview

2N3415 from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for amplification and switching in low-to-medium power circuits, with a 25 V V_CEO, 500 mA I_C, and 625 mW P_D at 25°C - commonly used in audio preamplifiers, relay drivers, and signal conditioning stages.

For engineers reviewing the 2N3415 datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, DC current gain range (h_FE = 180–540), saturation voltage (V_CE(sat) ≤ 0.3 V @ 50 mA), thermal resistance (R_θJA = 200 °C/W), and suitability for continuous collector currents up to 500 mA.

Technical Context

The 2N3415 operates as a silicon NPN BJT fabricated using Fairchild's Process 10, optimized for general-purpose linear amplification and saturated-switching applications. Its h_FE is specified at V_CE = 4.5 V and I_C = 2.0 mA, and small-signal h_fe matches DC gain under same bias conditions.

It supports operation across –55°C to +150°C junction temperature range, with absolute maximum ratings including 25 V V_CEO/V_CBO, 5.0 V V_EBO, and 500 mA I_C. Thermal derating begins above 25°C at 5.0 mW/°C, reflecting its TO-92 plastic package limitations.

Key Specifications

Pinout & Package

Package: TO-92 - 3-lead through-hole plastic package with standard B-C-E lead configuration (flat side facing viewer, leads down: Emitter–Base–Collector, left-to-right).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Compared with 2N3415, the 2N2222A offers higher voltage headroom and current capacity but reduced DC gain consistency, while the BC547 provides broader h_FE tolerance at lower power - making 2N3415 optimal for balanced gain, saturation, and thermal performance in 25 V/500 mA general-purpose roles.

Availability

2N3415 is available at Aetrix Electronics and suitable for audio preamplifiers, relay drivers, and DC motor control circuits requiring stable component supply and long-term obsolescence management.

Supply support for 2N3415 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 semiconductor manufacturer specializing in power management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016.

The 2N3415 belongs to Fairchild's legacy general-purpose BJT family, engineered for cost-effective, reliable amplification and switching in consumer, industrial, and educational electronics.

FAQ

What is the maximum collector-emitter voltage rating for the 2N3415?

The 2N3415 has a maximum collector-emitter voltage (V_CEO) rating of 25 V at T_A = 25°C. This rating assumes an open-base condition and must be derated at elevated temperatures. Exceeding this voltage risks avalanche breakdown and permanent device failure. Always maintain at least 20% margin below 25 V in practical designs using the 2N3415.

Does the 2N3415 support switching applications, and what is its typical V_CE(sat)?

Yes, the 2N3415 is qualified for switching use with a guaranteed V_CE(sat) ≤ 0.3 V at I_C = 50 mA and I_B = 3.0 mA. This low saturation voltage minimizes power dissipation during on-state operation, making the 2N3415 effective in relay drivers and low-duty-cycle PWM circuits where thermal management is constrained.

What package type does the 2N3415 use, and how are its pins arranged?

The 2N3415 uses the industry-standard TO-92 plastic package. With the flat side facing the viewer and leads pointing downward, the pin order from left to right is Emitter–Base–Collector. This configuration is consistent across Fairchild's 2N-series BJTs and supports manual soldering and wave-solder compatibility in the 2N3415.

What is the DC current gain (h_FE) range for the 2N3415, and at what conditions is it specified?

The 2N3415 exhibits a DC current gain (h_FE) range of 180 to 540, measured at V_CE = 4.5 V and I_C = 2.0 mA. This wide gain spread reflects process variation in Fairchild's Process 10 fabrication and requires design margining - especially in bias networks - to ensure stability across all units of the 2N3415.

Is the 2N3415 suitable for high-temperature environments, and what is its junction temperature limit?

Yes, the 2N3415 is rated for operation from –55°C to +150°C junction temperature. Its 150°C maximum TJ enables use in under-hood automotive modules or enclosed industrial enclosures, provided thermal resistance (R_θJA = 200 °C/W) and power dissipation are managed via board layout and airflow - critical for sustained reliability of the 2N3415.