onsemi 2N4401_D11Z

Overview

2N4401_D11Z from ON Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for medium-power amplification and switching applications with continuous collector current up to 600 mA, V_CEO = 40 V, and DC current gain (h_FE) ranging from 40 to 300 at I_C = 1.0–150 mA. It operates across –55 °C to +150 °C and is commonly used in low-voltage relay drivers, signal amplification stages, and digital logic interface circuits.

For engineers reviewing the 2N4401_D11Z datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package thermal resistance (R_θJA = 200 °C/W), saturation voltage (V_CE(sat) = 0.40 V at I_C = 150 mA), f_T = 250 MHz bandwidth, and compatibility with through-hole prototyping and industrial control PCB layouts.

Technical Context

The 2N4401_D11Z implements a silicon planar epitaxial NPN structure optimized for linear amplification and fast-switching operation. Its h_FE variation across I_C (40–300) supports both analog gain staging and saturated-switch biasing, while low storage time (t_s = 225 ns) enables reliable operation in pulse-width modulation (PWM) control circuits up to ~1 MHz.

Thermal design relies on its TO-92 package's 200 °C/W junction-to-ambient resistance and 625 mW maximum power dissipation at 25 °C, derating linearly at 5.0 mW/°C above ambient. Electrical robustness includes 60 V V_CBO, 6.0 V V_EBO, and guaranteed breakdown performance under pulsed conditions per JEDEC JESD22-A108.

Key Specifications

Pinout & Package

2N4401_D11Z is housed in a TO-92 3-lead plastic package with straight leads (JEDEC TO-92 compliant). Pin identification follows standard orientation: when viewing the flat side with leads pointing downward, left-to-right pin order is Emitter (E), Base (B), Collector (C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PN2222A and BC547B, the 2N4401_D11Z delivers optimal balance of current drive (600 mA), gain linearity (h_FE 40–300), and thermal performance (625 mW @ 25 °C) in the TO-92 form factor-making it ideal for cost-sensitive industrial controls where moderate power and proven reliability are prioritized over ultra-low noise or extreme current headroom.

Availability

2N4401_D11Z is available at Aetrix Electronics and suitable for relay driver circuits, digital logic level translation, audio pre-amplifier stages, and PWM motor control interfaces requiring stable component supply and long-term industrial availability.

Supply support for 2N4401_D11Z 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud computing, and consumer electronics.

The 2N4401_D11Z belongs to ON Semiconductor's legacy general-purpose BJT product line, engineered for robust, cost-effective discrete amplification and switching in non-critical analog and digital interface applications.

FAQ

What is the maximum continuous collector current rating for the 2N4401_D11Z?

The 2N4401_D11Z has a maximum continuous collector current (I_C) rating of 600 mA at T_A = 25 °C. This rating assumes proper PCB thermal relief and derates linearly by 5.0 mW/°C above ambient. At 70 °C ambient, usable I_C drops to approximately 425 mA to maintain junction temperature ≤ 150 °C. The 2N4401_D11Z must be operated within this limit to ensure long-term reliability and avoid thermal runaway.

Is the 2N4401_D11Z pin-compatible with other TO-92 NPN transistors like the PN2222A?

Yes, the 2N4401_D11Z uses the standard TO-92 package with E-B-C pinout (left-to-right when flat side faces viewer, leads down), matching the mechanical and electrical pin configuration of PN2222A, BC547, and 2N2222. This allows direct physical replacement in existing PCB footprints. However, differences in h_FE range, V_CE(sat), and f_T require verification of circuit biasing and timing margins when substituting the 2N4401_D11Z.

What is the typical current gain (h_FE) of the 2N4401_D11Z at 10 mA collector current?

The 2N4401_D11Z exhibits a typical DC current gain (h_FE) of 100 at I_C = 10 mA and V_CE = 1.0 V, with a guaranteed minimum of 80 and maximum of 300 under those conditions. This wide h_FE spread means circuit designs should use worst-case values (e.g., h_FE = 80) for saturation assurance or implement emitter degeneration for gain stability. The 2N4401_D11Z's h_FE remains usable down to I_C = 0.1 mA (min 20), supporting micro-power bias networks.

Can the 2N4401_D11Z be used in RF amplifier applications?

The 2N4401_D11Z has a current gain–bandwidth product (f_T) of 250 MHz, making it suitable for narrowband RF amplification up to ~50 MHz with appropriate impedance matching and neutralization. Its C_cb = 6.5 pF and C_eb = 30 pF limit high-frequency stability, and it lacks specified noise figure or S-parameters. For dedicated RF use, the 2N4401_D11Z is best applied in low-gain IF stages or harmonic generators-not primary LNA or transmitter output stages. Always validate performance with actual 2N4401_D11Z units in the target circuit.

Does the 2N4401_D11Z meet RoHS and lead-free requirements?

Yes, the 2N4401_D11Z complies with RoHS Directive 2011/65/EU and is manufactured with lead-free terminations and halogen-free molding compounds. ON Semiconductor confirms this part meets JEDEC J-STD-020 moisture sensitivity level (MSL) 1 and is qualified for reflow soldering per IPC/JEDEC J-STD-020. Full compliance documentation-including substance declarations and test reports-is available through ON Semiconductor's official product page for the 2N4401_D11Z.