2N5401 PNP Transistor

•Maximum voltage across collector and emitter: 150V

•Maximum current allowed trough collector: 600mA

•Maximum voltage across collector and base: 160 V

•Maximum voltage across base and emitter: 5V

2N5401 Transistor Overview

2N5401 is specifically designed to be used in high-voltage applications where the load consumes very little power (i.e. Current drawn by the load is low). These types of circuits can be seen in telephone systems. It can also be used when you want a simple switching device for high-voltage loads. Also, the component is cheap and easy to work with.

How to Use 2N5401 Transistor

2N5401 can be used like any general-purpose PNP transistor but for the sake of understanding the device working let us consider a simple application circuit as shown below.

In the above circuit, we are using 2N5401 as a simple switching device and the switching load is a small DC motor. The button here is for providing the trigger to the transistor and the 10K resistor is for limiting the current to the base and to avoid breaching the maximum voltage allowed at the base. Also as pointed out in the comment section below, considering the low gain of this transistor, it might be a better idea to use a low-value resistor like 100R for R1 to allow more base current. The circuit is powered from a negative voltage source of -5V DC as shown in the diagram.

Before going to work let us revise the typical characteristics of a PNP transistor:

•The device does not conduct when the current does not flow out of the base of the transistor or the device conducts only when the base current that flows out of the device reaches a threshold.

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