2N4401.NPN晶体管

2N4401.PIN配置

Pin Number	Pin Name	Description
1	Emitter	Current Drains out through emitter, normally connected to ground
2	Base	Controls the biasing of transistor, Used to turn ON or OFF the transistor
3	集电极	Current flows in through collector, normally connected to load

Features

• General purpose NPN Transistor
• High DC Current Gain (h_FE), typically 80 when I_C=10mA
• Continuous Collector current (I_C) is 500mA
• Collector-Emitter电压(V_CE) is 40 V
• 集电极基电压（V_CB）是60V.
• 发射极基击穿电压（V_BE）是6V.
• 过渡频率为100MHz
• Available in To-92 Package

Note:Complete technical details can be found in the2N4401.datasheetattached at the bottom of the page.

Alternative NPN Transistors

BC549，bc636，BC639,BC547，2n2369，2N3055,2N3904,2N3906,2SC5200,2N5551

2N4401.Equivalent Transistors

2N3904, 2N2222A

Brief Description on 2N4401 Transistor

2N4401.is aNPN transistorhence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin. 2N4401 has a gain value h_feof 500; this value determines the amplification capacity of the transistor. The maximum amount of current that could flow through the Collector pin is 800mA, hence we cannot connect loads that consume more than 500mA using this transistor. To bias a transistor we have to supply current to base pin, this current (I_B) should be limited to 5mA.

When this transistor is fully biased then it can allow a maximum of800mA流过收集器和发射器。该阶段称为饱和区域，并且允许集电体 - 发射器允许的典型电压（V._CE）或碱 - 发射器（v_BE) could be 200 and 900 mV respectively. When base current is removed the transistor becomes fully off, this stage is called as the Cut-off Region and the Base Emitter voltage could be around 660 mV.

Where 2N4401 Transistor is Used

The2N4401晶体管与常用的NPN晶体管非常相似2N2222。But there are two important features that differentiate the2n4401和2n2222。2N4401可以允许收集器电流高达500mA，并且还具有652mW的功耗，其可用于中等负载，而不是与2N2222进行比较，但可以驾驶负载BC547。

因此，如果您正在寻找可以切换负载或体面放大的NPN晶体管，那么2N4401可能是您项目的正确选择。

How to use 2N4401 Transistor

这种晶体管可以使用，也可以使用as a switch or as an amplifier。The Base-Emitter voltage of this transistor is 6V so you just have to supply this voltage across the base and emitter of the transistor to induce a base current into the transistor. This transistor will make it forward biased and thus closes the connection between collector and emitter. However one important thing to notice is the Base resistor a.k.a current limiting resistor. As the name suggests this resistor will limit the current flowing through the transistor to prevent it from damaging. The value for this resistor can be calculated using the formula

RB= VBE/ IB

To make things simple I have shown a simplified circuit to make a transistor as switch. In actual circuit modifications might be required. I have used a base voltage of 5V and a value of 1K as current limiting resistor

请注意，这里的电动机从12V电源汲取约500mA，因为2N4401具有电流额定电流额定值，该电路可能是BC547，晶体管应该被烧焦。

Applications

• Can be used to switch high current (upto 500mA) loads
• It can also be used in the various switching applications.
• 电机的速度控制
• 逆变器和其他再保险ctifier circuits
• 可用于达灵顿对。

2D-Model and Dimensions

2D dimensionswill help you in placing this component at the time of making circuit on perf board or a PCB.