onsemi 2N5550G

Overview

2N5550G from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for V_CEO = 140 V, I_C = 600 mA, P_D = 625 mW at T_A = 25°C, and f_T = 100 MHz - used in high-voltage linear amplification and switching stages of industrial power supplies and signal conditioning circuits.

For engineers reviewing the 2N5550G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal behavior, junction-to-case resistance (R_JC = 83.3°C/W), noise figure (NF = 10 dB), and real-world substitution guidance aligned with onsemi's Preferred Device designation.

Technical Context

The 2N5550G operates as a medium-power, high-voltage NPN bipolar junction transistor optimized for linear amplification and fast-switching applications. Its design supports stable DC current gain (h_FE = 60–250 across I_C = 1–50 mA) and low saturation voltages (V_CE(sat) = 0.15 V at I_C/I_B = 10), enabling efficient operation in Class-A amplifiers and relay drivers.

Thermal performance is defined by R_JA = 200°C/W (free-air) and R_JC = 83.3°C/W, allowing reliable operation up to +150°C junction temperature. Input capacitance (C_ibo = 30 pF) and output capacitance (C_obo = 6.0 pF) support bandwidth-critical designs where parasitic reactance must be minimized.

Key Specifications

Pinout & Package

2N5550G uses the standard TO-92 (Case 29-11) plastic package with straight or bent leads, Pb-free finish, and 3-pin through-hole mounting. Dimensions conform to ANSI Y14.5M (inch-based) and ASME Y14.5M (metric) standards, with body height 4.45–5.20 mm and lead pitch 2.54 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N5551G, the 2N5550G offers lower cost and adequate gain for general-purpose amplification, while MPSA42 trades bandwidth and gain for extreme voltage tolerance - making 2N5550G optimal for balanced performance in industrial signal chains where 140 V margin suffices.

Availability

2N5550G is available at Aetrix Electronics and suitable for industrial power supplies, audio signal conditioning, RF buffering, and PLC output stage designs requiring stable component supply, long-lifecycle support, and Pb-free compliance.

Supply support for 2N5550G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 2N5550G belongs to onsemi's legacy discrete transistor product line, engineered for reliability in high-voltage analog and switching applications where consistent h_FE, low noise, and thermal robustness are critical.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5550G?

The 2N5550G has a maximum collector-emitter voltage rating (V_CEO) of 140 Vdc, tested at I_C = 1.0 mAdc with base open. This rating defines the upper limit for safe DC or peak AC voltage applied between collector and emitter in active or cutoff regions. Exceeding 140 V risks avalanche breakdown and permanent device failure. Derating is recommended above +25°C ambient per the datasheet's thermal curves.

Does the 2N5550G have Pb-free packaging?

Yes, the 2N5550G is explicitly marked as a Pb-free device in onsemi's datasheet (Publication Order Number 2N5550/D, Rev. 5), compliant with RoHS Directive 2011/65/EU. The "G" suffix denotes Pb-free finish, and the package meets JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for standard reflow soldering processes without lead contamination.

What is the typical DC current gain (h_FE) of the 2N5550G at 1 mA collector current?

The 2N5550G exhibits a minimum h_FE of 60 and a maximum of 250 at I_C = 1.0 mAdc and V_CE = 5.0 Vdc, per onsemi's Electrical Characteristics table. Typical values fall within 100–200 under these conditions, but actual gain varies with temperature, bias point, and unit-to-unit process spread - design verification across the full operating range is required.

Can the 2N5550G be used in RF amplifier applications?

Yes, the 2N5550G supports RF amplifier use up to approximately 30 MHz due to its f_T = 100 MHz and low C_obo = 6.0 pF. It is commonly deployed in HF receiver buffers and broadband preamplifiers where moderate gain and noise performance are needed. For >50 MHz applications, devices with higher f_T and optimized RF packaging (e.g., SOT-23) are preferred.

What is the thermal resistance from junction to case (R_JC) for the 2N5550G?

The 2N5550G has a specified thermal resistance from junction to case (R_JC) of 83.3°C/W, measured under T_C = 25°C conditions. This value enables accurate calculation of junction temperature rise when mounted to a heatsink or PCB copper pour, supporting thermal design for continuous operation at up to 1.5 W dissipation - provided case temperature remains ≤25°C.