How to Select a Transistor

The transistor referred here is the bipolar junction transistor or BJT. Here is the complete guide on how to select a transistor. 1. Collector Current From the transistor datasheet, look for the collector current rating (IC). For instance the transistor MJD2873Q-13 from Diodes Incorporated, the collector current is specified in below table as Continuous Collector Current. The maximum limit is

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NPN Transistor applications and uses

NPN Transistor Principles and Practical Uses

Basic NPN Transistor Principles Universities are covering this topic very well but despite I still attempt to discuss NPN transistor principles that I think easier to understand for non technical people. NPN transistor is the name given to a bipolar junction transistor with two N type materials or negative carriers while there is only one P type material or positive

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Transistor Operation Mode Determination

Transistor operation mode is can easily be determined by using mathematical equations. Don’t worry; these are not difficult equations. There are three operation modes to operate the transistor. These are cut-off, saturation and linear. In cut-off, the transistor is simply not conducting; so it is not a problem to send the transistor in this region. You can simply do that

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Fixed Bias Configuration with a Divider Resistor in the Base Complete Analysis

This article will uncover the fixed bias configuration with a divider resistor complete analysis. Actually this is another variation of a fixed bias circuit as shown in Figure 87. The only difference of this circuit is the addition of a resistor RB2 as shown in the figure. At application wherein the base is not tied up with the supply , when

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Complete Analysis of a Fixed Bias Circuit using NPN Transistor

This article will uncover the complete analysis of a fixed bias circuit. Figure 73 below shows a simple common emitter configuration. It has a base resistor RB, collector resistor RC but no emitter resistor. In general, this biasing technique is called as non-emitter stabilized bias because there is no emitter resistor. By some, this is also called as the fixed bias.

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How to Saturate a PNP Transistor

PNP transistor is very useful in high side driving. A successful high side driving circuit starts with the proper understanding how to saturate a PNP transistor. Below are the steps to do it. How to Saturate a PNP Transistor – Step 1 Make sure that the circuit supplies are able to forward bias the emitter-base junction How to Saturate a

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How to know if a Transistor is Saturated?

There are several ways how to know if a transistor is saturated or not. It is very important that if you design a transistor to function as a switch that it should operate in the saturation and cutoff. Operation at cutoff is simply interrupting the bias of the transistor. However operating at saturation is not that easy. You need to

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How to Drive a Transistor into Hard Saturation

How to drive a transistor into hard saturation? In using a transistor to operate as a switch you must drive it into saturation. Saturation happens when the collector current cannot further increase despite there is base current increase. The saturation level of every transistor varies. The usual range is from 0.7V to ideally zero. For instance for a BC817-25 transistor,

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BJT Operation Modes

BJT operation modes are at cut-off, saturation and active or linear. At cut-off, simply the BJT is not operating, say the base-emitter voltage requirement is not meet. The corresponding collector-emitter voltage is the same with the collector supply. At saturation the other hand, the BJT is driven into the point wherein its collector current can no longer increase despite of the increase

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