Contents
What does it mean for a BJT to be saturated?
Saturation, as the name might imply, is where the base current has increased well beyond the point that the emitter-base junction is forward biased. In other words, the small base current can be made to control a much larger current between the collector and emitter.
What is unsaturated region?
The unsaturated zone is the portion of the subsurface above the groundwater table. The soil and rock in this zone contains air as well as water in its pores. Unlike the aquifers of the saturated zone below, the unsaturated zone is not a source of readily available water for human consumption.
What is a saturated transistor?
Saturation is the on mode of a transistor. A transistor in saturation mode acts like a short circuit between collector and emitter. In saturation mode both of the “diodes” in the transistor are forward biased. That means VBE must be greater than 0, and so must VBC. In other words, VB must be higher than both VE and VC.
What is a highly saturated color?
Color saturation refers to the intensity of color in an image. As the saturation decreases, the colors appear to be more washed-out or pale. A highly saturated image has vivid, rich and bright colors, while an image with a low saturation will veer towards a scale of grey.
What is saturated in physics?
The act of saturating or the process of being saturated. (physics) The condition in which, after a sufficient increase in a causal force, no further increase in the resultant effect is possible; e.g. the state of a ferromagnetic material that cannot be further magnetized.
Why does a BJT transistor have to be saturated?
BJT transistor will be saturated the moment the Ic will not follow the linear relation of: I c = H F E ∗ I b. Thus all we have to do is to limit the Ic from reaching this value. Since I b is determined by the value of the resistor connected to the base and the driving voltage on its other end, it is easy to force I b to any value.
When does the BJT operate in the saturation region?
The BJT operates in the saturation region when its collector current is not dependent on the base current and has reached a maximum. The condition for this to happen is that both the base-emitter and the base-collector junctions should be forward-biased.
How are the PN junctions in a BJT biased?
In order for a BJT to operate properly, the two pn junctions must be correctly biased with external DC voltages. In both cases the base-emitter (BE) junction is forward-biased and the base-collector (BC) junction is reverse-biased. This condition is called forward-reverse bias.
Which is a dependent current in a BJT?
Fig. 6 shows the unsaturated BJT as a device with a current input and a dependent current source in the output circuit for an npn. The input circuit is a forward-biased diode through which there is base current. The output circuit is a dependent current source (diamond-shaped element) with a value that is dependent on IB.