onsemi 2N3903_D26Z

Overview

2N3903_D26Z from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for low-power amplification and switching applications up to 100 mA collector current. It features a V_CEO of 40 V, V_CBO of 60 V, and operates across –55°C to +150°C. Its TO-92 package supports cost-sensitive consumer, industrial control, and signal conditioning circuits.

For engineers reviewing the 2N3903_D26Z datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain (h_FE) variation with I_C, saturation voltage at defined drive conditions, thermal resistance (R_θJA = 200°C/W), noise figure (6.0 dB @ 100 µA), and TO-92 mechanical compatibility in automated assembly.

Technical Context

The 2N3903_D26Z operates as a discrete NPN BJT with fixed-emitter biasing capability and linear small-signal amplification up to 100 MHz (h_fe = 2.5 @ f = 100 MHz). Its base-emitter junction exhibits V_BE(sat) = 0.65–0.95 V depending on I_C/I_B ratio, while output capacitance (C_ob = 4.0 pF) and input capacitance (C_ib = 8.0 pF) support stable high-frequency operation under 10 V_CE.

Switching performance is characterized by t_d = 35 ns, t_r = 35 ns, t_s = 175 ns, and t_f = 50 ns under standardized pulse test conditions (pulse width ≤ 300 µs, duty cycle ≤ 2.0%). Thermal design requires derating above 25°C at 5.0 mW/°C due to P_D = 625 mW at T_A = 25°C.

Key Specifications

Pinout & Package

2N3903_D26Z is housed in a standard TO-92 plastic package with 3 leads, compatible with through-hole and tape-and-reel (EOL code D26Z) automated placement. Lead configuration follows JEDEC TO-92 outline: Emitter (lead 1), Base (lead 2), Collector (lead 3), with flat side facing viewer and leads downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N2222A and BC547B, the 2N3903_D26Z offers tighter V_CE(sat) spec (0.2 V), lower noise (6.0 dB), and proven thermal behavior in TO-92-making it preferred for cost-sensitive, moderate-speed switching and audio-critical preamps where gain variability is acceptable.

Availability

2N3903_D26Z is available at Aetrix Electronics and suitable for industrial sensor interfaces, audio pre-amplifier stages, and digital logic level shifting requiring stable component supply and long-term obsolescence management.

Supply support for 2N3903_D26Z 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The 2N3903_D26Z belongs to Fairchild's legacy general-purpose BJT family, engineered for broad utility in amplification and switching where reliability, manufacturability, and TO-92 compatibility are prioritized over ultra-high speed or RF performance.

FAQ

What is the maximum continuous collector current rating for the 2N3903_D26Z?

The 2N3903_D26Z has an absolute maximum continuous collector current (I_C) rating of 200 mA at T_A = 25°C. However, the device is functionally specified for use up to 100 mA in amplification and switching roles, aligning with its thermal dissipation limit of 625 mW and R_θJA = 200°C/W. Exceeding 100 mA continuously requires careful thermal analysis and board-level heatsinking.

Does the 2N3903_D26Z have a documented noise figure, and under what conditions is it measured?

Yes, the 2N3903_D26Z has a documented noise figure of 6.0 dB. This value is measured under standardized conditions: V_CE = 5.0 V, I_C = 100 µA, source resistance R_S = 1.0 kΩ, and bandwidth from 10 Hz to 15.7 kHz. The specification appears in the "Small Signal Characteristics" section of the Fairchild datasheet and reflects performance relevant to audio-frequency preamplifier applications.

What is the pin configuration of the 2N3903_D26Z in its TO-92 package?

The 2N3903_D26Z uses the standard JEDEC TO-92 pinout: when viewing the flat side of the package with leads pointing downward, lead 1 (left) is the Emitter, lead 2 (center) is the Base, and lead 3 (right) is the Collector. This E-B-C arrangement is confirmed in Fairchild's TO-92 packaging documentation and matches the "Style A" tape-and-reel configuration referenced by EOL code D26Z.

Can the 2N3903_D26Z be used in switching applications, and what are its key timing parameters?

Yes, the 2N3903_D26Z is explicitly rated for switching use. Its key timing parameters-measured under pulse test conditions (pulse width ≤ 300 µs, duty cycle ≤ 2.0%)-are: delay time t_d = 35 ns, rise time t_r = 35 ns, storage time t_s = 175 ns, and fall time t_f = 50 ns, all at V_CC = 3.0 V and I_C = 10 mA. These values support reliable operation in digital logic interfacing and PWM-driven loads up to ~1–2 MHz.

Is the 2N3903_D26Z RoHS compliant and halogen-free?

The 2N3903_D26Z was manufactured by Fairchild Semiconductor prior to its 2016 acquisition by ON Semiconductor. While the original datasheet does not carry explicit RoHS or halogen-free declarations, Fairchild's post-2006 product lines-including later revisions of the 2N3903 family-were transitioned to RoHS-compliant and halogen-free packaging. For compliance-critical designs, Aetrix Electronics recommends verifying material content via lot-specific Certificates of Conformance or consulting ON Semiconductor's cross-reference documentation for successor parts.