onsemi 2N3417

Overview

2N3417 from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for amplification and switching applications with continuous collector current up to 500 mA and V_CEO = 50 V. It features h_FE = 180–540 at I_C = 2.0 mA, V_CE = 4.5 V, and is housed in a TO-92 plastic package. It is commonly used in low-power audio preamplifiers, relay drivers, and signal switching circuits.

For engineers reviewing the 2N3417 datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain range, saturation voltage under defined drive conditions, thermal resistance (R_θJA = 200 °C/W), maximum junction temperature (150 °C), and TO-92 mechanical compatibility in space-constrained PCB layouts.

Technical Context

The 2N3417 operates as a silicon NPN BJT optimized for linear amplification and saturated switching in discrete analog and digital interface stages. Its h_FE binning (180–540) enables predictable biasing across production lots, while V_CE(sat) ≤ 0.3 V at I_C = 50 mA / I_B = 3.0 mA supports efficient low-voltage switching.

Thermal design relies on its R_θJA = 200 °C/W and R_θJC = 83.3 °C/W ratings, with derating of 5.0 mW/°C above 25 °C ambient. The device is rated for operation from –55 °C to +150 °C junction temperature and uses Fairchild's Process 10 fabrication.

Key Specifications

Pinout & Package

2N3417 is supplied in a standard TO-92 plastic package with lead configuration Base–Collector–Emitter (B–C–E) when viewed from the flat side with leads pointing downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N3417, the 2N2222A offers reduced gain consistency but wider legacy support, while the PN2222A provides identical performance with enhanced manufacturing traceability and environmental compliance-both require no PCB layout changes due to TO-92 pinout equivalence.

Availability

2N3417 is available at Aetrix Electronics and suitable for audio preamplifier stages, relay driver circuits, and LED current switching applications requiring stable component supply and long-term obsolescence management.

Supply support for 2N3417 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 company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The 2N3417 belongs to Fairchild's legacy general-purpose BJT product line, engineered for cost-effective, robust amplification and switching in industrial, consumer, and educational electronics.

FAQ

What is the maximum collector current rating for the 2N3417?

The 2N3417 has a maximum continuous collector current (I_C) rating of 500 mA at T_A = 25 °C. This rating assumes proper thermal management; derating is required above 25 °C ambient per the 5.0 mW/°C specification. Pulse operation may allow higher transient currents, but must be verified against duty cycle and pulse width limits defined in the datasheet.

Is the 2N3417 pin-compatible with the 2N2222A?

Yes, the 2N3417 is pin-compatible with the 2N2222A in the TO-92 package, sharing the same B–C–E lead arrangement when viewed from the flat side. Both devices use identical mechanical outlines and mounting footprints, allowing direct substitution without PCB modification-though h_FE and saturation characteristics differ and must be validated in circuit.

What is the typical h_FE value of the 2N3417 at 2 mA collector current?

The 2N3417 exhibits a minimum h_FE of 180 and a maximum of 540 at V_CE = 4.5 V and I_C = 2.0 mA, per its official Fairchild datasheet. This wide gain range reflects process binning and requires circuit design to accommodate variation-common practice includes emitter degeneration or feedback to stabilize operating point.

Does the 2N3417 have a specified transition frequency (f_T)?

No, the official Fairchild 2N3417 datasheet does not specify transition frequency (f_T). It is characterized for DC and low-frequency small-signal gain (h_fe at 1 kHz), not RF performance. For high-frequency amplification, designers should select transistors explicitly rated for f_T > 100 MHz, such as the MMBT2222A or BC847 series.

What is the thermal resistance from junction to ambient (R_θJA) for the 2N3417?

The 2N3417 has a specified R_θJA of 200 °C/W under standard test conditions (free-air, no heatsink). This value assumes the TO-92 package is mounted on a typical FR-4 PCB with minimal copper; adding thermal relief pads or copper pour can reduce effective R_θJA by up to 30%, depending on layout.