BC238 NPN Transistor Pinout Datasheet

Introduction

The BC238 NPN transistor is a popular general-purpose silicon transistor designed for low noise, low power amplification, and switching applications. It belongs to the well-known BC23x transistor family, which includes BC237, BC238, and BC239, widely used in audio preamplifiers, small-signal processing, and general-purpose electronic circuits. With its moderate current gain, low collector current, and high reliability, the BC238 is an ideal choice for both analog and digital designs.

This transistor is primarily used in low-power amplifier circuits, where signal clarity and stability are important. Its maximum collector current of 100mA and collector-emitter voltage of 25V make it suitable for applications such as signal amplification in radios, microphones, and preamp stages. The TO-92 package ensures easy handling and compact mounting on printed circuit boards (PCBs).

BC238 NPN Transistor

The BC238 offers similar electrical characteristics to its counterparts BC237 and BC239, but it stands out due to its balanced noise performance and voltage handling. It performs well in low-frequency amplifier stages and is frequently found in educational projects, consumer electronics, and DIY audio equipment.

BC238 Pinout

Pin Configuration

Pin#	Pin Name	Pin Description
1	Collector (C)	Current flows through this terminal from collector to emitter when the transistor is conducting.
2	Base (B)	Controls the transistor’s operation; a small base current controls a larger collector current.
3	Emitter (E)	Connected to ground or the negative supply line; current exits through this terminal.

BC238 Pin Configuration

Key Features

General-purpose NPN silicon transistor
Low noise and stable performance in amplifier circuits
Suitable for small signal amplification and switching
Available in compact TO-92 plastic package
Moderate voltage and current ratings for hobbyist and professional use
Complementary to BC328 (PNP)
Ideal for educational, experimental, and low-power applications

Characteristics

Transistor Type: NPN
Collector-Emitter Voltage (Vceo): 25V
Collector-Base Voltage (Vcbo): 30V
Emitter-Base Voltage (Vebo): 5V
Collector Current (Ic max): 100mA
DC Current Gain (hFE): 110 – 800 (typical range)
Transition Frequency (fT): 100MHz
Power Dissipation (Ptot): 500mW
Operating Junction Temperature: -65°C to +150°C
Package Type: TO-92

Comparison : BC237 vs BC238 vs BC239

The BC237, BC238, and BC239 transistors are all part of the same low-noise, small-signal NPN family. They share the same TO-92 package, current handling capability, and general-purpose nature. The main difference lies in their maximum voltage ratings and noise performance.

The BC237 offers a moderate collector-emitter voltage rating of 45V, making it versatile for most signal applications. The BC238 supports slightly higher voltage levels (up to 50V), while the BC239 is optimized for ultra-low noise audio applications, making it a preferred choice in high-fidelity amplifiers and sensitive input stages. In general, they are electrically interchangeable for most low-power circuits, with the BC239 offering the best noise performance, followed by BC238 and BC237.

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Key Applications of BC238 Transistor

Audio preamplifier and small signal amplifier circuits
Low noise audio frequency (AF) amplifier stages
Switching small loads in electronic devices
Signal processing and waveform generation circuits
DIY audio projects and electronic kits
General-purpose electronic circuits in educational labs

PNP Complementary Transistor

BC328 is the PNP complementary transistor for BC238.
It provides similar voltage and current ratings, making it a suitable counterpart for push-pull amplifier stages and complementary pair designs.

Equivalent of BC238 NPN Transistor

BC237, BC239, 2N3904, 2N2222, BC548, BC549, S8050
These transistors can often replace BC238 in circuits with similar electrical requirements. Always check pinout and voltage ratings before substitution.

Datasheet of BC238 NPN Transistor

Click the following Button to download the datasheet of BC238 Transistor :

Download Datasheet

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