Forward Biasing Characterstics
The characteristics of a diode under forward bias:
- Conductivity Increases
In forward bias, the positive terminal of the voltage source is connected to the p-type (positive) semiconductor material, and the negative terminal is connected to the n-type (negative) semiconductor material. This arrangement reduces the potential barrier at the junction, allowing charge carriers (electrons in the n-type material and holes in the p-type material) to move across the junction more easily.
- Reduction in Barrier Potential
The forward bias reduces the potential barrier at the p-n junction. This barrier is essentially the energy barrier that prevents the flow of majority carriers across the junction.As the forward voltage is increased, the barrier potential decreases.
- Current Flow
With the reduced barrier potential, charge carriers can overcome the potential barrier and move across the junction.Current starts to flow through the diode in the direction of the external voltage.
- Low Resistance
Under forward bias, the diode exhibits low resistance, allowing for efficient conduction of current.
- Forward Voltage Drop
The forward voltage drop (Vf) is the voltage at which the diode starts conducting significantly. This voltage varies depending on the type of diode (e.g., silicon diodes typically have a forward voltage drop of around 0.7 volts).
Forward Bias
Forward Bias is a term commonly used in semiconductor electronics, particularly concerning diodes and transistors. A diode is considered to be in forward bias when its p-side is connected to the positive side of a power supply and its n-side to the negative side. In the case of an NPN transistor, the base-emitter junction is forward-biased, which means the base is positive relative to the emitter. Conversely, for a PNP transistor, the base is negative relative to the emitter.
In this article, we will discuss all Forward Biases including Forward Bias of PN junctions and transistors.
Table of Content
- What Is Forward Biasing?
- Forward Biasing Characterstics
- Forward Bias P-N Junction Diode
- Forward Current Equation
- Forward and Reverse Bias
- Applications of Forward Bias