Hey Everyone! I hope you all are having fun and looking forward for happy weekend. I am here to give you a daily dose of sound knowledge so you can develop some skills in engineering field. Today, I am going to uncover the details on the Introduction to 2sa1215. It is bipolar silicon PNP (positive-negative-positive) transistor. It is made up of two layers of P doped material and one layer of N doped material. I'll give you the brief overview of this device, what it does and what are its major applications? Let's hop on the board and dive into the details of this PNP transistor.

#### Introduction to 2sa1215

• 2sa1215 is a bipolar PNP silicon transistor where one layer of N doped material lies between the two layers of P doped material.
• The small current at the base side is used to handle the large current at the emitter and collector side.
• In PNP transistor, P side represents the polarity of voltage at the emitter side which is positive and N represents the polarity of base side which is negative. In PNP transistor, Emitter is always positive with respect to base.
• 2sa1215 has a current gain that ranges between 50 to 180.
• Some people get deceived by the dust like surface on this transistor, which actually is not a dust, but an anti-static powder.
• It is also called high frequency multi emitter transistor.
##### 2sa1215 Pinout
Pinout of 2sa1215 is shown in the figure below. 2sa1215 consists of three terminals 1: Base 2: Collector 3: Emitter
• Current will flow from collector to emitter and current carries are holes.
• Sometimes 2s prefix is not written on the component. 2sa1215 can be written as A1215.
• 2sc2921 is the complementary NPN transistor of 2sa1215.
• 2sa1215 can be replaced by 2sa1493, or 2sa1216
##### Circuit Symbol 2s1215
Circuit symbol of 2s1215 is shown in the figure below. It is made up of two P layers and one N layer.
• Polarity at the emitter side is positive as compared to base and collector.
• Base comes with negative polarity with respect to emitter.
• Small current at the base side is used to handle the large current at the collector and emitter.
• PNP also works similar to NPN, but in case of PNP current direction will be reversed and current carriers used in case of PNP will be holes rather than electrons that are current carriers in NPN transistors.
• Current at the emitter side is equal to the sum of current at base and collector side.
##### Maximum Rating of 2sa1215
Maximum rating of 2sa1215 is shown in the figure below.
• Collector base voltage is 160 V and is denoted by Vcb.
• Collector emitter voltage is also 160 and is denoted by Vce.
• Power dissipation of this transistor is 150W.
• Collector current and base current are 15 A and 4 A repectively.
• Transition frequency is 50MHZ.

##### How to Identify Genuine 2s1215
There are genuine and fake (Chinese) transistors out there. However, you don't need to worry about that, I am going to give you three ways by which you can check if transistor is genuine of fake.
• 1: Genuine copy of transistor 2s1215 comes with a weight of 18.4g, which its Chinese copy only weighs 15.7g.
• 2: Genuine copy consists of two layer metal heat sink, while Chinese copy only consists of one layer metal heat sink.
• 3: Transistors can also be classified on the basis of their output. Genuine copy gives good output, while in case of Chinese copy, output is broken.
##### Difference between NPN and PNP transistors
• Both NPN and PNP transistors works in a similar way with the exception that Base is positive in case of NPN transistor and is negative in case of PNP transistor. NPN transistor sources the current from its base to the transistor while in case of PNP it sinks the current into its base side.
• NPN and PNP are also different with respect to medium used to carry current. Current carriers in NPN transistors are electrons while current carries are holes in case of PNP transistors. Holes are collected by the collector.
##### Applications
• It can be used for high audio output stage.
• It is also used as general purpose amplifier and for switching applications.
That's all for today. I hope you have got an idea of this PNP transistor. If you have any question you can ask me in the comment section below. I'll try my best to resolve your query as soon as possible. Thanks for reading the article. Get ready for next article. Till then, stay happy and blessed. Good Bye!