Npn bipolar junction transistor, Electrical Engineering


2093_NPN Bipolar Junction Transistor.png

Figure: The symbol of an NPN Bipolar Junction Transistor.

NPN is one of the two sorts of bipolar transistors, where the letters "N" (negative) and "P" (positive) stands for the majority charge carriers in the different regions of the transistor. Several bipolar transistors employed today are NPN, since electron mobility is higher than as compared to the hole mobility in semiconductors, permitting much greater currents and much faster operation.

NPN transistors contain a layer of P-doped semiconductor (the "base") among the two N-doped layers. A small current that is entering the base in common-emitter mode is amplified in the collector output. In other words, an NPN transistor is "on" while the base of it is pulled high relative to the emitter.

The arrow (in figure) in the NPN transistor symbol is on the emitter leg and points in the direction of the conventional current flow while the device is in forward active mode.

One mnemonic device for making out the symbol for the NPN transistor is "not pointing in, or 'not pointing, no' "

Posted Date: 1/10/2013 6:41:46 AM | Location : United States

Related Discussions:- Npn bipolar junction transistor, Assignment Help, Ask Question on Npn bipolar junction transistor, Get Answer, Expert's Help, Npn bipolar junction transistor Discussions

Write discussion on Npn bipolar junction transistor
Your posts are moderated
Related Questions
Discuss DMA definition. Direct memory access (DMA) is a process wherein an external device takes over the control of system bus by the CPU. Direct memory access is for high-sp

How is bias compensation in transistor is done using thermistors and sensistor

Consider the RC circuit of Figure (a) with R = 2 ,C = 5F,and i(t) = I = 10 A (a dc current source). Find the expressions for the capacitor voltage vC(t) and the capacitor current

When three resistors R1, R2 and R3 are connected in parallel as shown in the diagram. For these resistors the equivalent resistance is given by: a. Derive a rule to

stack Pointer (SP) It is also a 16 bit  register and a  memory  pointer similar to  program counter. It holds  the memory  address of the  top of the stack. Stack is a  part of

1) Study the CPLD Design Project Brief to gain an understanding of the project, and the System Specification, Circuit Description, Pre-processing and Post-processing Requirements f

fir and iir filter design

Q. What do you mean by Sequential Blocks? Neglecting propagation delays, which are measures of how long it takes the output of a gate to respond to a transition at the input of

The resistance of a 5 m length of wire is 600Ω.Determine: a)  the resistance of an 8 m length of the same wire, b)  the length of the same wire when the resistance is 420Ω

Explain Load Flow Analysis The method commonly used for load flow analysis is the nodal analysis. The nodal analysis method is given in many books on circuit theory and is base