Zener diodes regulate voltage by exploiting their unique characteristic of maintaining a constant voltage across their terminals once the voltage exceeds a certain threshold called the "Zener voltage" or "breakdown voltage." Here's how it works:
Reverse Bias Operation: Zener diodes are operated in reverse bias mode, meaning the voltage is applied in the opposite direction of their normal forward bias operation.
Breakdown Region: When the reverse voltage applied across the Zener diode exceeds the Zener voltage, the diode enters the breakdown region. In this region, the Zener diode starts to conduct significantly, allowing current to flow in the reverse direction.
Constant Voltage Drop: In the breakdown region, the Zener diode maintains a relatively constant voltage drop across its terminals, regardless of changes in the applied voltage (within certain limits). This constant voltage is approximately equal to the Zener voltage specified for the diode.
Regulation: By connecting the Zener diode in parallel with a load, the voltage across the load remains nearly constant at the Zener voltage, even when there are fluctuations in the input voltage or changes in the load resistance. This provides voltage regulation and helps stabilize the output voltage of the circuit.
In summary, Zener diodes regulate voltage by operating in the breakdown region and maintaining a constant voltage drop across their terminals, which is determined by their Zener voltage.
No comments:
Post a Comment