2N5551 Description

The 2N5551 is an NPN high-voltage transistor in a TO-92 plastic package. Its PNP complements are 2N5400 and 2N5401. The 2N5551 is designed for general-purpose applications such as amplification and switching. It has a maximum collector to emitter voltage of 160V and a maximum collector to base voltage of 180V, making it suitable for circuits operating below 160V. The maximum output load this transistor can handle is 600mA, and the maximum power dissipation of the collector is 625mW.

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2N5551 Features

- Package Type: TO-92

- Transistor Type: NPN

- Max Collector Current (IC): 6A or 600mA

- Max Collector-Emitter Voltage (VCE): 160V

- Max Collector-Base Voltage (VCB): 180V

- Max Emitter-Base Voltage (VBE): 6V

- Max Collector Dissipation (Pc): 625 mW

- Max Transition Frequency (fT): 100 MHz

- Minimum & Maximum DC Current Gain (hFE): 80 - 250

- Max Storage & Operating Temperature: -55 to +150 Centigrade

Where to use 2N5551

The 2N5551 is an NPN amplifier transistor with an amplification factor (hfe) of 80 when the collector current is 10mA. It also exhibits decent switching characteristics, with a transition frequency of 100MHz, making it suitable for amplifying low-level signals.

Because of these features, the transistor is commonly utilized for amplifying audio or other low-power signals. Therefore, if you are in need of an NPN transistor for your amplifier circuit, then this transistor might be the appropriate choice.

How to use 2N5551

The 2N5551 NPN transistor finds wide application in amplification. A simple, bare minimum circuit for a transistor to function as an amplifier is depicted below. Additionally, the simulation graph illustrating the amplified output sine wave is available.

How to utilize 2N5551

The 2N5551 NPN transistor finds wide application in amplification. A very simple and essential circuit for a transistor to operate as an amplifier is illustrated below. Additionally, the simulation graph displaying the amplified output sine wave can be observed.

In this setup, the input sine wave with a magnitude of 8mV (yellow color) is amplified to 50mV (pink color) as depicted in the graph. Within the circuit, resistors R3 and R4 establish a potential divider determining the Emitter-Base voltage (VBE). Resistor R1 functions as the load resistor, while resistor R2 serves as the emitter resistor. Altering the value of RL will impact the amplification of the output wave.

Typically, a transistor acts as a current amplifier, implying that the current flowing through the base will be amplified in the current flowing through the collector. This amplification is contingent upon the amplification factor (hfe), which is 80 for 2N5551. Thus, the collector current will be amplified by 80 times compared to the base current.

Ic = βIb

Another pertinent current we consider is the emitter current (IE). Due to transistor action, we assume the emitter current value is nearly equal to the collector current, although the discrepancy between the two can be determined by the value of α. Ordinarily, the collector current value is expressed as:

IE = IC + IB

The output is acquired across the collector, denoted as the Collector-Emitter voltage (VCE). This output voltage is contingent upon the input voltage (Vcc, here 12V) minus the voltage drop across the load resistor (R1). Consequently, the output voltage Vout can be described as:

Vout = VCE = (Vcc – IcRc)

Frequently Asked Question

What is 2N5551?

2N5551 is an NPN bipolar junction transistor primarily used for general-purpose amplification and gas discharge display drivers. It consists of three terminals known as the emitter, base, and collector and comes in a TO-92 package.