2N5551 Transistor (TO-92) Pinout, Features, Equivalents, Datasheet

The 2N5551 is a silicon NPN transistor and housed in a TO-92 suitable for high-voltage tasks in switching and amplification.

It can handle up to 180V for collector-base and 160V for collector-emitter voltages, with a maximum collector current of 600mA. The emitter-base voltage is 6V, and this transistor can dissipate up to 625mW of power. With a minimum Beta (β) of 80, the 2N5551 transistor ensures reliable performance across various applications.

2N5551 Pinout Configuration

The pin configuration of the 2N5551 transistor is as follows:

Pin No.	Name	Description
1	Emitter	Electrons emitted from the emitter into the first PN.
2	Base	Controls the biasing of the transistor.
2	Collector	Electrons Emitted from Emitter Collected by the Collector.

Absolute Maximum Ratings of 2N5551

The quick technical specifications and features of the 2n5551 transistor are given below:

• Transistor Type: Si
• Polarity: NPN
• Emitter-Base Voltage (Veb max.): 6V
• Collector Power Dissipation (Pc max.): 625mW
• Collector-Base Voltage (Vcb max.): 180V
• Collector-Emitter Voltage (Vce max.): 160V
• Collector Current (Ic max.): 600mA
• Operating Junction Temperature (Tj): -55°C to 150°C
• Transition Frequency (ft): 100MHz
• Collector Capacitance (Cc): 6pF
• Forward Current Transfer Ratio (hFE min.): 80
• Noise Figure (dB): -
• Package: TO-92

Note: Complete Technical Details can be found in the 2N5551 transistor datasheet given at the end of this page.

2N5551 PNP Complementary

There are no complementary PNP transistors to the 2N5551.

2N5551 Equivalent Transistor

Transistor	Type	Polarity	Pc	Vcb	Vce	Veb	Ic	Tj	Ft	Hfe	Caps
2N5551BU	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
2N5551C	Si	NPN	0.625	180	160	6	.6	150	300	6	TO92
2N5551G	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92, SOT89
2N5551K	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
2N5551TA	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
2N5551TF	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
2N5551TFR	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
H2N5551	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92
H5551	Si	NPN	0.625	180	160	6	.6	150	100	6	TO92

These nine transistors have similar features and can be used as replacements for the 2N5551 in terms of their package, emitter-base voltage, transition frequency, and forward current transfer ratio. But there might be slight differences in pin layout. Please verify before using them in a PCB or project.

Applications of 2N5551

1. Switching load of up to 0.6A
2. high voltage amplification
3. Signal amplification
4. Gas discharge display drivers
5. LED drivers
6. Voltage regulators

2N5551: 2D Model and Dimensions

If you are designing a PCB or perf board with this component, the following picture from the 2N5551 datasheet will be useful to determine its package type and dimensions.

Component Datasheet

2N5551 Datasheet

2N5551 Safe Operating Guidelines

It is recommended not to push the 2N5551 transistor to its absolute limits. It's best to stay at least 20% below its maximum ratings. For example, while it can handle a maximum load of 600mA, it's safer to avoid exceeding 480mA. Similarly, its maximum load voltage is 160V, so it's advisable to stay below 128V. Additionally, ensure the transistor's temperature stays between -55°C and 150°C for proper operation.