SS8050 NPN Epitaxial Silicon Transistor: Ideal for Small Power Amplification and Switching Applications

Ⅰ. Introduction of SS8050

Ⅱ. Technical parameters of SS8050 transistor

Ⅲ. NPN-type transistor and PNP-type transistor

Ⅳ. How to use SS8050 transistor?

Ⅴ. Electrical characteristics of SS8050 transistor

Ⅵ. What is the difference between SS8050 and S8050?

Ⅶ. How to test whether SS8050 transistor works normally?

Triode, also known as bipolar transistor, crystal triode, is a semiconductor device that controls the current. Its function is to amplify weak signals into electrical signals with larger amplitudes, and is also used as a contactless switch. Crystal transistor has the role of current amplification, is the core component of electronic circuits. Today we will introduce a common NPN epitaxial silicon transistor SS8050.

SS8050 is a NPN-type low-power transistor, belonging to the general-purpose transistor. Its complementary pair is the SS8550 transistor with PNP structure. It adopts TO-92 package and has the advantages of high current amplification, low noise figure, good high frequency characteristics, etc. It is widely used in various electronic devices and circuits. SS8050 mainly consists of three regions, which are the emitter region, the base region and the collector region. Among them, the transmitting region is an N-type region, the base region is a P-type region, and the collector region is an N-type region. This structure makes SS8050 bipolar and can realize the function of current amplification.

SS8050 transistor replacements:

• MPS650G

• MPS651

• MPS8050

• S9013

• 2N5551

• 2N5830

• Manufacturer: Onsemi / Fairchild

• Length: 4.58 mm

• Width: 3.86 mm

• Height: 4.58 mm

• Package / Case: TO-92-3

• Packaging: Tape & Reel (TR)

• Power Dissipation: 1 W

• Transistor Polarity: NPN

• Configuration: Single

• Mounting Style: Through Hole

• Operating Temperature: -65°C ~ 150°C

• Continuous Collector Current: 1.5 A

• Product Category: Bipolar Transistors - BJT

1. NPN type triode (SS8050)

Current relationship: IE=IC+IB

We can know the state of the triode by the voltage of the three pins to ground.

• When VC>VB>VE, that is, the emitter is positively biased and the collector is reverse biased, the triode is in the amplified state;

• When VB>VC>VE, the emitter is positively biased, the collector is positively biased, and the triode is in saturation;

• When VB>VE>VC, the emitter is reverse biased, the collector is reverse biased, and the triode is in the cutoff state;

(The forward bias and reverse bias of the triode are distinguished based on the PN junction of the triode. If the PN voltage is positive, it is forward biased, otherwise it is reverse biased)

2. PNP type triode (SS8550)

Current relationship: IC=IE+IB

We can know the state of the triode by the voltage of the three pins to ground.

• When VE>VB>VC, that is, the emitter is positively biased, the collector is reverse biased, the triode is in the amplification state;

• When VE>VC>VB, the emitter is positively biased, the collector is positively biased, and the triode is in saturation;

• When VB>VE>VC, the emitter is reverse biased, the collector is reverse biased, and the triode is in the cutoff state;

(The forward bias and reverse bias of the triode are distinguished based on the PN junction of the triode. If the PN voltage is positive, it is forward biased, otherwise it is reverse biased)

SS8050 is mainly used in amplification, switching and regulation circuits, and its common application scenarios include power management, audio power amplifiers, voltage detection circuits and DC regulator circuits. When using SS8050, we need to pay attention to the following points:

1. Operating state

The operating state of SS8050 is divided into amplification area, saturation area and cutoff area. Under different operating states, its current amplification coefficient is different. We need to choose the appropriate operating state according to the specific application scenario.

2. Polarity judgment

SS8050 is a kind of PNP type triode, its polarity is opposite to NPN type triode. Before use, we need to confirm its polarity and whether the pins are connected correctly.

Generally speaking, the right side of the collector will be marked with the letter "C" or the symbol "+", and the left side of the emitter will be marked with the letter "E" or the symbol " -". E" or the symbol " - ". The base electrode is the control electrode of the PNP type triode, and its main function is to control the output current. The middle part of the base is narrower and shorter than the other two pins. We can judge its position by observing these markings.

3. Circuit connection

Commonly used connection methods for SS8050 are common emitter, common collector and common base. The common emitter connection can be used in power amplifiers and switching circuits; the common collector connection is suitable for voltage following and buffer circuits; the common base connection is suitable for high frequency and modulation circuits.

Values are at TA=25°C unless otherwise noted.

SS8050 and S8050 are two different transistor models. Despite their similar names, their electrical properties and parameters may differ. The differences between the two are as follows.

1. Parameters

In terms of voltage, the maximum collector voltage of the SS8050 is generally 30 V, while the maximum collector voltage of the S8050 is generally 40 V. In terms of current gain, the current gain of the SS8050 is generally in the range of 120 dB to 300 dB, while the current gain of the S8050 is generally in the range of 60 dB to 150 dB.

2. Applications

SS8050 is widely used in AC power supply and other occasions, while S8050 is suitable for low-voltage and low-power occasions, such as burglar alarm and other circuits.

3. Package

SS8050 generally use SOT-23 package, while S8050 generally use TO-92 package. 

We can use a multimeter to test the on and off status of SS8050. By setting the multimeter to diode test mode, you can measure the resistance between the base and emitter, and the resistance between the collector and emitter. We set the range switch of the digital multimeter to the two-pole position. The red test lead is connected to the base of SS8050, and the black test lead is connected to the collector and emitter respectively. At this time, the tube should show a conduction voltage drop, generally between 0.6mv and 0.7mv. Then, we swap the red and black test leads. If the resistance value shows infinity, it means the tube is normal.

Overall, the SS8050 is widely used because of its low cost and ease of use. Before using this chip, we should have a basic understanding of its parameters and usage in order to better apply it in our projects.

Frequently Asked Questions

1. What is the replacement of SS8050?

Transistor SS8050 can be replaced with MPS650, MPS650G, MPS651, MPS651G, MPS8050.

2. What are the uses of SS8050 transistor?

This transistor is used for audio amplification as well as a wide range of general-purpose applications in electronic circuits, such as switching.

3. What is the difference between S8050 and S8550 transistor?

The circuit using the S8050 (NPN transistor) will light up when the button is pressed, which means it is receiving a high-level conduction circuit; The circuit that uses the S8550 (PNP transistor) will light up when it is released, which means it is receiving a low-level conduction circuit.

4. What are the main applications of the SS8050 transistor?

The SS8050 is commonly used for amplification and switching in electronic circuits. It can be used in audio amplifiers, signal amplification, and low to medium power switching applications.