onsemi 2N5550TF

Overview

2N5550TF from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon general-purpose amplifier transistor in TO-92 package, rated for 140 V V_CEO, 600 mA I_C, and 625 mW P_D, commonly used in low-noise audio preamplifier stages and high-voltage switching interfaces.

For engineers reviewing the 2N5550TF datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, DC current gain linearity at 1–50 mA, thermal derating above 25°C, and TO-92 lead-form compatibility with through-hole PCB layouts.

Technical Context

This discrete NPN bipolar junction transistor features epitaxial base construction for improved f_T (100–300 MHz) and low noise figure (10 dB at 10 Hz–15.7 kHz), enabling stable small-signal amplification in wideband analog front-ends. Its 160 V V_CBO and 140 V V_CEO support operation in medium-voltage linear and switching circuits up to 120 V DC rails.

Thermal design relies on FR-4 PCB mounting with minimum land pattern (R_θJA = 200°C/W); derating is 5.0 mW/°C above 25°C ambient. The device exhibits h_FE = 60–250 across 1–10 mA I_C, with V_CE(sat) ≤ 0.25 V at I_C = 50 mA / I_B = 5 mA, confirming suitability for active-load and driver-stage configurations.

Key Specifications

Pinout & Package

2N5550TF is housed in a JEDEC TO-92 3-lead molded plastic package with straight leads (Tape and Reel packing). Standard lead configuration: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA42 and BC547C, the 2N5550TF offers balanced trade-offs: sufficient voltage headroom for 100 V systems, usable h_FE linearity across 1–10 mA, and verified low-noise performance-making it a preferred choice for general-purpose medium-voltage analog amplification where neither extreme voltage nor ultra-high gain dominates the design.

Availability

2N5550TF is available at Aetrix Electronics and suitable for audio preamplifier stages, high-voltage switch interfaces, and linear voltage regulator pass elements requiring stable component supply, long-term obsolescence management, and tape-and-reel delivery for automated assembly.

Supply support for 2N5550TF 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 supplier of energy-efficient semiconductor components, specializing in power management, analog, and discrete devices for industrial, automotive, and consumer applications.

The 2N5550TF belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, designed for cost-sensitive, medium-voltage analog and switching functions in through-hole assembled equipment.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5550TF?

The 2N5550TF has a guaranteed minimum collector-emitter breakdown voltage (BV_CEO) of 140 V at I_C = 1 mA and I_B = 0. This rating applies under DC or pulsed conditions with proper heatsinking and ambient temperature control. Operation above this voltage risks irreversible avalanche failure, and design margins should maintain V_CE ≤ 120 V for long-term reliability in continuous applications.

Does the 2N5550TF have a specified noise figure, and under what conditions is it measured?

Yes, the 2N5550TF has a typical noise figure (NF) of 10 dB, measured at I_C = 250 μA, V_CE = 5 V, R_S = 1 kΩ, and frequency range 10 Hz to 15.7 kHz. This value reflects its suitability for low-level signal amplification in audio and sensor interfaces where preserving signal-to-noise ratio is critical. Actual NF may vary ±1.5 dB across production lots and must be validated in the final circuit layout.

What is the thermal resistance junction-to-ambient (R_θJA) for the 2N5550TF, and how does it affect power dissipation?

The 2N5550TF has an R_θJA of 200°C/W when mounted on a standard FR-4 PCB (76 mm × 114 mm × 1.57 mm) with minimum land pattern. At 25°C ambient, its 625 mW maximum power dissipation drops by 5.0 mW per °C rise, limiting usable power to ~375 mW at 85°C ambient. Board-level copper area and airflow significantly influence real-world thermal performance.

Is the 2N5550TF pin-compatible with other TO-92 NPN transistors like the 2N2222A or BC547?

No-the 2N5550TF uses the standard TO-92 pinout (Emitter-Base-Collector = Pins 1-2-3), which matches the 2N2222A and BC547 physically, but electrical characteristics differ substantially. While pinout alignment allows socket substitution, the 2N5550TF's 140 V V_CEO and 10 dB NF are not replicated by those parts; using them interchangeably risks overvoltage failure or degraded noise performance in sensitive designs.

What packaging format does the 2N5550TF use, and how does it impact automated assembly?

The 2N5550TF is supplied in Tape and Reel (T&R) format, compliant with EIA-481 standards for TO-92 devices. This enables direct feeding into pick-and-place machines for high-volume through-hole assembly. The straight-lead configuration (per Figure 11) ensures reliable insertion into wave-solder pallets and eliminates need for lead-forming prior to soldering, reducing process steps and mechanical stress on the package.