onsemi 2N4401RLRM

Overview

2N4401RLRM from onsemi is an NPN silicon general-purpose transistor in TO-92 package, rated for 40 V_CEO, 600 mA_C, and 625 mW at T_A = 25°C, with DC current gain (h_FE) ranging from 20 to 300 depending on operating point, commonly used in low-power switching and linear amplification circuits.

For engineers reviewing the 2N4401RLRM datasheet, pinout, applications, or equivalent options, this discrete BJT supports design validation for signal conditioning, relay drivers, LED control, and small-signal amplification where cost-effective, through-hole NPN performance is required.

Technical Context

The 2N4401RLRM operates as a standard bipolar junction transistor with base-controlled current amplification, exhibiting f_T = 250 MHz at I_C = 20 mA, V_CE = 10 V, enabling use in audio-frequency and low-speed digital switching. Its V_BE(sat) ranges from 0.75 V to 0.95 V at I_C = 150 mA, I_B = 15 mA, supporting predictable saturation behavior in switch-mode operation.

Thermal resistance R_JA = 200 °C/W and R_JC = 83.3 °C/W define its thermal limits under ambient and case-mounted conditions; maximum junction temperature is +150°C, with storage down to −55°C, confirming suitability for industrial-grade non-automotive environments.

Key Specifications

Pinout & Package

2N4401RLRM uses the industry-standard TO-92 (Case 29, Style 1) plastic package with axial leads and through-hole mounting. The device has three terminals arranged in a linear configuration with standardized mechanical dimensions per ON Semiconductor's CASE 29-11 drawing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PN2222A and BC547B, the 2N4401RLRM offers balanced trade-offs: sufficient voltage margin for 24 V systems, robust 600 mA drive, and broad h_FE coverage-making it ideal for cost-sensitive, medium-power discrete switching where TO-92 form factor and legacy compatibility are essential.

Availability

2N4401RLRM is available at Aetrix Electronics and suitable for relay driver circuits, LED current switches, audio pre-amplifier stages, and signal level shifter designs requiring stable component supply and long-term obsolescence management.

Supply support for 2N4401RLRM 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 discrete, analog, and logic solutions for automotive, industrial, cloud, and IoT applications.

The 2N4401RLRM belongs to onsemi's legacy general-purpose transistor product line, designed for cost-sensitive, high-reliability linear and switching functions in industrial controls, consumer electronics, and power management subsystems.

FAQ

What is the pin configuration of the 2N4401RLRM?

The 2N4401RLRM uses TO-92 package with Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector (Style 1). This matches JEDEC standard orientation and is verified in the official ON Semiconductor datasheet revision 2. The 2N4401RLRM pinout supports common-emitter, common-base, and common-collector configurations without modification.

Does the 2N4401RLRM have Pb-free packaging options?

Yes, the 2N4401RLRM is offered in standard form, while the 2N4401RLRMG variant is explicitly marked as Pb-free and RoHS-compliant. Both share identical electrical specifications and TO-92 mechanical dimensions. The 2N4401RLRM itself is not Pb-free unless specified by the G suffix; always verify part marking and packaging documentation for compliance.

What is the maximum continuous collector current for the 2N4401RLRM?

Per the ON Semiconductor datasheet, the 2N4401RLRM has a maximum continuous collector current (I_C) of 600 mA at T_A = 25°C. Derating applies above 25°C (5 mW/°C for power, proportional current reduction for thermal safety), and pulsed operation allows higher peak currents if duty cycle and pulse width remain within specification limits.

Can the 2N4401RLRM replace the 2N2222 in existing designs?

The 2N4401RLRM shares TO-92 packaging and E-B-C pinout with the 2N2222, but differs in key parameters: higher I_C (600 mA vs. 800 mA), lower V_CEO (40 V vs. 40 V same), and broader h_FE range (20–300 vs. 35–300). It can substitute in most low-to-medium current applications, but verify V_CE(sat) and switching speed requirements-especially in high-frequency or high-gain feedback circuits-before replacement.

What is the transition frequency (f_T) of the 2N4401RLRM and how does it affect circuit design?

The 2N4401RLRM has a minimum f_T of 250 MHz at I_C = 20 mA, V_CE = 10 V. This indicates usable small-signal gain up to approximately 50 MHz in practical amplifier designs. For switching applications, f_T correlates with achievable rise/fall times (t_r, t_f ≤ 20 ns); thus, the 2N4401RLRM supports clean digital edges in sub-20 MHz logic interfacing and audio-band amplification without instability.