The term “bias” in electronics refers to the direction of the voltage applied to a device, such as a diode. There are two types diode biases: forward bias or reverse bias.
Both types of bias can have different effects on diodes and their operation. It is important to understand the difference between reverse bias and forward bias in order to understand the behavior of diodes and their applications.
Forward bias occurs when the voltage is applied in a direction that allows current flow through the diode. Reverse bias happens when the voltage is applied in the opposite direction and blocks current flow. Both types of bias have different effects on the characteristics of diode and can be used for different purposes.
Difference between Forward bias and Reverse bias
| Factors | Forward biasing | Reverse biasing |
| Voltage polarity | In forward biasing, the positive voltage (terminal) is connected to the p-type region and negative terminal to the n-type region. | In reverse biasing, the positive voltage (terminal) is connected to the n-type region and negative terminal to the p-type region. |
| Current flow | In forward biasing, the diode conducts current. | While in reverse biasing, it blocks the current flow. |
| Voltage drop | In forward biasing, the voltage drop across the diode is very less. | In reverse biasing, the voltage drop is very high. |
| Diode resistance | In forward biasing, the diode exhibits low resistance to the current flow, allowing for an easy flow of current. | On the other side in reverse biasing, the resistance of the diode is high, blocking the current flow. |
| Depletion region width | In forward biasing, the depletion region width decreases allowing for an easy flow of current. | While in reverse biasing, the depletion region width increases, blocking the current flow. |
| Dynamic resistance | In forward biasing, the dynamic resistance of the diode is low, allowing for a smooth flow of current. | While in reverse biasing, the dynamic resistance is high, blocking the current flow. |
| Current-Voltage characteristic | In forward biasing, the current-voltage characteristic of the diode is linear. | While in reverse biasing, the characteristic is non-linear. |