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Hence, the current that moves into the base pin increases. Interestingly, this model is the transistor’s most potent mode because it changes the device to an amplifier. And this voltage must be greater than the collector. So, for a transistor to be inactive reverse mode, the voltage at the emitter should be more than the base. The reverse-active mode happens when a transistor amplifies and conducts but the current moves in the opposite direction (from emitter to collector). And the deal shows that V C must be a bit higher than V E for the transistor to enter saturation mode. The value of the V CE(Sat) ranges from 0.05 – 0.2V. And you can define V CE(Sat) as the voltage from the collector to an emitter that the transistors need for saturation. Manufacturers often represent this voltage in transistor datasheets as V CE(sat) (CE saturation voltage). As a result, you’ll notice a small voltage drop at the nodes. So, at room temperature, we can estimate that many transistors have a voltage drop of about 0.6V.įurther, it’s vital to note that you may not have excellent conduction between the collector and emitter.
![transistor definition transistor definition](https://i.pcmag.com/imagery/encyclopedia-terms/transistor-tran4.gif)
You can represent voltage drop with a few abbreviations like V d, V th, etc., and the value differs between transistors and even temperature. In other words, for a transistor to enter saturation, the V BE has to be higher than the threshold voltage. Additionally, it means that V B is higher than V C and V E. And forward biased is when the V BE and V BC are more than zero. When a transistor is in saturation mode, it’s “On.” Plus, it behaves like a short circuit between the collector and emitter.Īlso, this mode makes the transistor’s diodes become forward biased. That said, the operation modes include: Saturation Mode So, V BC is the voltage that moves from the base to the collector, and the V BE refers to the current moving from the floor to the emitter. And the modes show the current flowing through them (i.e., from an NPN’s collector to emitter).įurther, if you want to know a transistor’s mode, you have to pay attention to the relationship and voltages of the three pins. Transistors operate in four different modes because they are non-linear devices. As a result, there will be distortions in the output signals. And it’s because the base-collector doesn’t remain in the reverse-biased mode. Also, when you modify the configuration of a transistor, it quickly changes its saturation level.īut, it’s crucial to note that when you configure transistors, the device doesn’t reach its saturation point. And it’s because the mirror can’t handle more drink. So, a transistor operates within a saturated area when the current attains the highest specified value.įor instance, when you pour liquid into a glass till it reaches the brim-it’s in a saturated state. Saturation happens when a system reaches its threshold or maximum value. So, let’s get started! What Is Transistor Saturation? Later in this article, we’ll discuss more on this topic, show you the operation modes, calculation, and more. But the transistor has to be in a saturated state to turn the DC device on or off. And you can achieve this by using transistor switches. When you’re dealing with low DC devices, it’s normal to switch them Off or On. The Collector current (I C) flows through the Collector-Base region due to holes.Transistor Saturated? What does it mean? Well, this term can only make sense if you’re a designer or engineer that’s quite familiar with transistor switches. The remaining holes which do not recombine with electrons in Base, that holes will further travel to the Collector. The holes are majority charge carriers to flow the Emitter current. This current is known as Emitter current (I E).
![transistor definition transistor definition](https://i.pinimg.com/originals/b7/37/97/b737978dc7b4e06f1c334208d16832a9.png)
Therefore, almost all holes of Emitter will cross the depletion region and enter into the Base layer.īecause of the movement of holes, the current will flow through the Emitter-Base junction. But The number of electrons in the Base is very small because it is a very lightly doped and thin region. The loss of holes in the emitter is equal to the number of electrons present in the Base layer. Simultaneously, very few electrons enter in Emitter from the base and recombine with the holes. Therefore, a very large number of holes from emitter cross the depletion region and enter the Base. The Emitter-base junction is in forward bias. While the Collector-Base junction is in reverse bias and hence the depletion region at Collector-Base junction is wide. Due to this type of bias, the depletion region at Emitter-Base junction is narrow, because it is connected in forward bias.