B1238 PDF – Power PNP Transistor (-80V, -0.7A) – Rohm

This post explains for the transistor.

The Part Number is B1238, 2SB1238.

The function of this transistor is -80V, -0.7A, PNP Transistor.

Manufacturer: Rohm

Preview images :

B1238 pinout datasheet


A PNP medium power transistor is a specific type of PNP (Positive-Negative-Positive) bipolar junction transistor (BJT) designed to handle moderate power levels. It is commonly used in electronic circuits where moderate power amplification or switching capabilities are required.

PNP medium power transistors find applications in a wide range of electronic circuits, including audio amplifiers, power supply circuits, motor control circuits, voltage regulators, and general-purpose amplification and switching circuits.


1. PNP BJT: The transistor is of PNP polarity, which means it has an N-type semiconductor material as the base and two P-type semiconductor regions as the emitter and collector.

2. Medium Power Handling: The PNP medium power transistor is designed to handle power levels that are higher than low-power transistors but lower than high-power transistors. The exact power rating may vary depending on the specific transistor model.

3. Voltage and Current Ratings: The transistor will have specified voltage and current ratings that indicate the maximum voltage and current it can safely handle without exceeding its limits. These ratings typically include the maximum collector-base voltage (Vcb), maximum collector-emitter voltage (Vce), and maximum collector current (Ic).

4. Current Gain: The current gain, also known as the DC current gain or hFE, represents the amplification capability of the transistor. A higher current gain allows for smaller input currents to control larger output currents.


B1238 pdf

Absolute maximum ratings ( Ta=25°C )

1. Collector to Base Voltage: Vcbo = -80V
2. Collector to Emitter Voltage: Vceo = -80V
3. Emitter to Base Voltage: Vebo = -5V
4. Collector Current: Ic = -0.7A
5. Collector Dissipation: Pc = 1W
6. Junction Temperature: Tj = 150°C
7. Storage Temperature: Tsg = -55 ~ +150°C

B1238 Datasheet