onsemi 2N5401

Overview

2N5401 from onsemi is a PNP silicon small-signal amplifier transistor in TO-92 package, rated for V_CEO = 150 V, I_C = 600 mA, and P_D = 625 mW at T_A = 25°C. It delivers h_FE = 50–240 (at I_C = 1–50 mA), f_T = 300 MHz, and V_CE(sat) ≤ 0.5 V, commonly used in high-voltage linear amplification and switching stages of discrete audio preamps and power supply control circuits.

For engineers reviewing the 2N5401 datasheet, pinout, applications, or equivalent options, key selection criteria include its 150 V V_CEO, 300 MHz f_T, TO-92 mechanical compatibility, low noise figure (8.0 dB), and verified performance across −55°C to +150°C junction temperature range.

Technical Context

The 2N5401 operates as a general-purpose PNP bipolar junction transistor optimized for medium-voltage, medium-current linear amplification and active switching. Its design emphasizes high breakdown voltage (V_CBO = 160 V, V_CEO = 150 V) and stable DC current gain (h_FE ≥ 50 at I_C = 1 mA, ≥ 40 at I_C = 50 mA) under varying thermal conditions.

It supports small-signal operation up to 300 MHz (f_T) with C_obo = 6.0 pF and exhibits low saturation voltages (V_CE(sat) ≤ 0.5 V at I_C/I_B = 10), enabling efficient use in Class-A amplifiers and emitter-follower buffers where voltage headroom and thermal stability are critical.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-11, Style 1), Pb-free, through-hole mounting with 2.54 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA92 and BC557B, the 2N5401 uniquely balances 150 V ruggedness, 300 MHz bandwidth, and TO-92 compatibility-making it optimal for mid-voltage analog signal chains where both headroom and speed matter.

Availability

2N5401 is available at Aetrix Electronics and suitable for high-voltage amplifier stages, discrete switching drivers, and linear regulator pass elements requiring stable component supply across industrial control, test equipment, and legacy audio hardware programs.

Supply support for 2N5401 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 focused on energy-efficient electronics, delivering power management, analog, sensing, and connectivity solutions.

The 2N5401 belongs to onsemi's legacy discrete transistor family designed for robust, cost-effective PNP amplification and switching in industrial, automotive, and consumer analog systems.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5401?

The 2N5401 has a maximum collector-emitter voltage (V_CEO) rating of 150 Vdc, verified per the official onsemi datasheet (2N5400/D, Rev. 1, December 2005). This rating applies under DC conditions with I_C = 1.0 mAdc and I_B = 0. Exceeding this voltage risks irreversible breakdown. The 2N5401 is therefore suitable for circuits operating up to 120 V rails with safety margin, unlike the 2N5400 (120 V).

Is the 2N5401 available in Pb-free packaging?

Yes, the 2N5401ZL1G variant is explicitly designated as Pb-free in the onsemi ordering table. It uses the same TO-92 package as standard 2N5401 but complies with RoHS requirements. Other Pb-free versions include 2N5401G (bulk) and 2N5401RL1G (tape & reel). All Pb-free variants retain identical electrical specifications and thermal performance as their non-Pb-free counterparts.

What is the typical DC current gain (h_FE) of the 2N5401 at 10 mA collector current?

At I_C = 10 mAdc and V_CE = 5.0 Vdc, the 2N5401 exhibits h_FE ranging from 40 (minimum) to 240 (maximum), per the "ELECTRICAL CHARACTERISTICS" table in the onsemi datasheet. This wide spread reflects process variation; design margins should assume h_FE ≥ 40 for worst-case bias stability. The 2N5401's h_FE remains usable down to −55°C, supporting cold-environment applications.

Can the 2N5401 be used as a direct replacement for the 2N5400 in existing designs?

The 2N5401 can replace the 2N5400 in most designs due to identical pinout, package, and complementary NPN pairing (2N5400/2N5401), but only if the higher 150 V V_CEO and 160 V V_CBO ratings are acceptable. Key differences include higher breakdown voltages and slightly lower f_T (300 MHz vs. 400 MHz for 2N5400). No PCB changes are needed, but verify thermal dissipation and gain stability under target operating conditions for the 2N5401.

What is the thermal resistance from junction to case (R_JC) for the 2N5401?

The 2N5401 has a thermal resistance from junction to case (R_JC) of 83.3 °C/W, as specified in the "THERMAL CHARACTERISTICS" section of the onsemi datasheet. This value assumes proper mounting to a heatsink via the collector tab (pin 3). Combined with R_JA = 200 °C/W (junction-to-ambient, no heatsink), it enables safe operation at full 625 mW dissipation only with adequate heatsinking or derating above 25°C ambient.