onsemi BC338-25ZL1

Overview

BC338-25ZL1 from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 25 V_CEO, 800 mA_C, and 625 mW dissipation at 25°C ambient. It delivers h_FE = 160–250 at I_C = 100 mA, V_CE = 1.0 V, with f_T = 210 MHz and V_CE(sat) ≤ 0.7 V at I_C = 500 mA/I_B = 50 mA - used in low-voltage switching and linear amplification stages of consumer audio and power supply feedback circuits.

For engineers reviewing the BC338-25ZL1 datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, thermal behavior, TO-92 terminal mapping, safe operating area limits, and direct alternatives for discrete BJT replacement in cost-sensitive analog and switching designs.

Technical Context

The BC338-25ZL1 operates as a medium-current, medium-voltage NPN bipolar junction transistor optimized for linear amplification and saturated switching. Its 25 V_CEO rating targets 24 V rail systems, while its 83.3°C/W junction-to-case thermal resistance supports reliable operation under moderate heatsinking.

It exhibits DC current gain (h_FE) tightly binned to 160–250 at 100 mA collector current, with 210 MHz transition frequency enabling RF preamp use up to ~30 MHz. Saturation voltage remains ≤0.7 V under 10:1 overdrive, supporting efficient low-side switch operation in relay drivers and LED controls.

Key Specifications

Pinout & Package

BC338-25ZL1 uses the industry-standard TO-92 (Case 29, Style 17) plastic package with 3 leads, 4.45–5.20 mm height, and Pb-free finish. Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - confirmed per marking diagram and ordering table on page 4 of ON Semiconductor's BC337/D datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC337-25ZL1 and BC547C, BC338-25ZL1 uniquely balances 25 V operation, 800 mA current handling, and 160–250 h_FE - making it optimal for 24 V embedded switching where voltage margin is constrained but current demand exceeds 100 mA.

Availability

BC338-25ZL1 is available at Aetrix Electronics and suitable for audio pre-amplifier stages, DC motor speed control, power supply feedback circuits, and LED constant-current drivers requiring stable component supply and long-term manufacturability.

Supply support for BC338-25ZL1 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 specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The BC338-25ZL1 belongs to onsemi's legacy general-purpose bipolar transistor family, designed for cost-sensitive, high-reliability linear amplification and switching in consumer, industrial, and communication equipment.

FAQ

What is the maximum collector-emitter voltage rating for BC338-25ZL1?

The BC338-25ZL1 has a maximum collector-emitter voltage (V_CEO) rating of 25 V DC. This value is specified under test conditions of I_C = 10 mA and I_B = 0, and represents the absolute maximum before breakdown occurs. Exceeding this voltage risks permanent device failure, so BC338-25ZL1 should not be used in circuits where transient or steady-state V_CE exceeds 25 V - such as unclamped inductive loads or 36 V supply rails without protection.

Is BC338-25ZL1 lead-free and RoHS compliant?

Yes, BC338-25ZL1 is manufactured with a Pb-free (RoHS-compliant) finish, as confirmed in the "Ordering Information" section of the official ON Semiconductor BC337/D datasheet. The "G" suffix variant (BC338-25ZL1G) explicitly denotes Pb-free packaging, and the base part BC338-25ZL1 is also supplied in Pb-free form per onsemi's standard policy effective September 2005. Both variants meet JEDEC J-STD-609 Category 1 requirements.

What is the typical DC current gain (h_FE) of BC338-25ZL1 at 100 mA collector current?

The BC338-25ZL1 exhibits a typical DC current gain (h_FE) of 200 at I_C = 100 mA, V_CE = 1.0 V, and T_A = 25°C, with a guaranteed minimum of 160 and maximum of 250. This h_FE binning is consistent across the BC337−25/BC338−25 group and enables predictable biasing in amplifier and switch designs without individual device screening.

Can BC338-25ZL1 be used as a direct replacement for BC547 in existing designs?

No, BC338-25ZL1 is not a direct replacement for BC547 due to key differences: BC547 has higher V_CEO (45 V) and h_FE (420–800), but lower I_C (100 mA). While both share TO-92 pinout (C-B-E), substituting BC338-25ZL1 into a BC547 circuit may cause overcurrent stress if the original design relies on BC547's lower current capability for thermal safety. Always revalidate SOA, gain, and saturation behavior before substitution.

What is the thermal resistance junction-to-ambient (R_θJA) for BC338-25ZL1 in free air?

The thermal resistance junction-to-ambient (R_θJA) for BC338-25ZL1 is 200°C/W under standard test conditions (free-air, no heatsink, PCB-mounted per JEDEC standards). This value means that at 625 mW dissipation, the junction temperature will rise 125°C above ambient - so operation at full power requires ambient ≤25°C or additional PCB copper area to reduce effective R_θJA.