onsemi BC338_J35Z

Overview

BC338_J35Z from ON Semiconductor is an NPN epitaxial silicon transistor designed for low-power switching and amplification in general-purpose analog and digital circuits. It features a 30 V V_CEO, 800 mA I_C, 625 mW power dissipation, 200 °C/W thermal resistance, and h_FE range of 160–400 at I_C = 100 mA - commonly used in AF driver stages and low-power output stages of consumer audio equipment.

For engineers reviewing the BC338_J35Z datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, DC current gain classification (h_FE = 25), collector-emitter breakdown voltage (25 V), saturation voltage (0.7 V @ 500 mA), and suitability for linear amplification versus saturated switching.

Technical Context

The BC338_J35Z operates as a discrete bipolar junction transistor with fixed NPN polarity and epitaxial base construction, enabling stable gain and low leakage across ambient temperatures up to 150 °C. Its design supports both active-region amplification (e.g., preamplifier gain stages) and hard-switching operation (e.g., relay drivers), with verified performance at V_CE = 1 V and I_C = 100 mA or 300 mA.

It shares complementary pairing with BC328 (PNP counterpart) and belongs to the BC337/BC338 family standardized under JEDEC TO-92 packaging. Electrical behavior is characterized by BVCES = 30 V, V_BE(on) = 1.2 V at I_C = 300 mA, and f_T = 100 MHz - confirming utility in audio-frequency signal paths but not RF applications.

Key Specifications

Pinout & Package

BC338_J35Z is housed in a JEDEC-standard TO-92 3-lead plastic package with straight or bent leads, compatible with through-hole PCB assembly and standard tape-and-reel handling. The package provides mechanical robustness and thermal path via leadframe conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC338_J35Z, BC338-25 offers identical performance in all validated parameters and is a direct nomenclature-aligned variant, whereas PN2222A trades gain and capacitance for higher voltage rating and bandwidth - making it preferable only when those specific parameters dominate the design.

Availability

BC338_J35Z is available at Aetrix Electronics and suitable for audio pre-amplifier stages, LED driver switches, relay driver circuits, and signal-level shifter applications requiring stable component supply and long-term manufacturability.

Supply support for BC338_J35Z 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, sensor, and logic devices for automotive, industrial, and consumer markets.

The BC338_J35Z belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and optimized for cost-sensitive, high-volume linear and switching applications in consumer electronics and industrial controls.

FAQ

What is the maximum collector-emitter voltage rating for BC338_J35Z?

The BC338_J35Z has a maximum collector-emitter voltage rating (V_CEO) of 25 V under standard test conditions (I_C = 10 mA, I_B = 0). This value is confirmed in the official BC337/BC338 datasheet Rev. 1.5 and defines the absolute upper limit for safe operation in common-emitter configurations. Exceeding this voltage risks avalanche breakdown and permanent device failure. Always include margin in design - e.g., limit V_CE to ≤18 V in 24 V systems.

Does BC338_J35Z have a specified h_FE range, and how is it classified?

Yes, BC338_J35Z is classified as h_FE = 25, corresponding to a DC current gain range of 160–400 at V_CE = 1 V and I_C = 100 mA. This classification is explicitly documented in the "hFE Classification" table of the BC337/BC338 datasheet. The "25" suffix denotes the middle gain bin - distinct from BC338-16 (100–250) and BC338-40 (250–630) - ensuring predictable base drive requirements in production designs.

What package type does BC338_J35Z use, and is it RoHS compliant?

BC338_J35Z uses the JEDEC-standard TO-92 3-lead plastic package with straight or bent leads, as confirmed in the "Physical Dimensions" section of the BC337/BC338 datasheet. While the original Fairchild documentation predates full RoHS enforcement, ON Semiconductor certifies all active BC338 variants - including BC338_J35Z - as lead-free and RoHS-compliant per EU Directive 2011/65/EU, with material declarations available upon request.

Can BC338_J35Z be used as a direct replacement for BC338-25?

Yes, BC338_J35Z is functionally and electrically identical to BC338-25 - sharing the same die, TO-92 package, absolute maximum ratings, and electrical characteristics. The "J35Z" suffix reflects Fairchild's internal marking convention prior to ON Semiconductor's nomenclature harmonization; no PCB layout, schematic, or firmware changes are needed when substituting BC338_J35Z for BC338-25 in existing designs.

What is the thermal resistance (R_θJA) of BC338_J35Z, and how does it affect PCB layout?

The BC338_J35Z has a junction-to-ambient thermal resistance (R_θJA) of 200 °C/W under standard FR-4 board conditions (76 mm × 114 mm, minimum land pattern). This means each watt of dissipated power raises the junction temperature by 200 °C above ambient - so at 625 mW, ΔT ≈ 125 °C. To maintain safe operation below 150 °C junction temperature, keep ambient ≤25 °C or increase copper area around the collector pad to reduce R_θJA empirically.