How can diodes be used in voltage limiters to protect sensitive components?
1 Answer
Diodes can be used in voltage limiters to protect sensitive components from excessive voltage levels. Voltage limiters are also known as voltage clamping or voltage protection circuits. They are designed to prevent voltage spikes or transient overvoltages from damaging sensitive electronic components or circuits. Diodes are essential components in these voltage limiter circuits and are usually employed in two common configurations: the Zener diode voltage limiter and the Schottky diode voltage limiter.
Zener diode voltage limiter:
Zener diodes are special types of diodes that are designed to operate in reverse-biased mode. When a Zener diode is reverse-biased, it exhibits a controlled breakdown or Zener voltage, and once this voltage is reached, the diode starts conducting to maintain a nearly constant voltage across its terminals. This characteristic makes Zener diodes suitable for voltage regulation and protection purposes.
In a Zener diode voltage limiter circuit, the Zener diode is connected in parallel to the load or sensitive component that needs protection. When the input voltage exceeds the Zener diode's breakdown voltage, it starts to conduct, effectively "clamping" the voltage across the load to the Zener voltage level. This prevents the voltage from rising further and protects the sensitive component from excessive voltage.
Schottky diode voltage limiter:
Schottky diodes are another type of diode that has a lower forward voltage drop compared to standard diodes. This characteristic makes them ideal for fast switching applications and voltage clamping circuits.
In a Schottky diode voltage limiter circuit, the Schottky diode is connected in parallel to the sensitive component. When the input voltage exceeds the forward voltage drop of the Schottky diode (usually around 0.3 to 0.5 volts), the diode starts conducting, providing a low-impedance path for the excess current to flow. This effectively limits the voltage across the sensitive component, protecting it from overvoltage.
Both Zener and Schottky diode voltage limiters offer different characteristics and are chosen based on the specific application requirements. When designing voltage limiters, it's essential to choose diodes with appropriate breakdown voltage (for Zener diodes) or forward voltage drop (for Schottky diodes) to ensure effective protection of the sensitive components. Additionally, other components like resistors may be added to fine-tune the voltage clamping levels and enhance the performance of the voltage limiter circuit.
Zener diode voltage limiter:
Zener diodes are special types of diodes that are designed to operate in reverse-biased mode. When a Zener diode is reverse-biased, it exhibits a controlled breakdown or Zener voltage, and once this voltage is reached, the diode starts conducting to maintain a nearly constant voltage across its terminals. This characteristic makes Zener diodes suitable for voltage regulation and protection purposes.
In a Zener diode voltage limiter circuit, the Zener diode is connected in parallel to the load or sensitive component that needs protection. When the input voltage exceeds the Zener diode's breakdown voltage, it starts to conduct, effectively "clamping" the voltage across the load to the Zener voltage level. This prevents the voltage from rising further and protects the sensitive component from excessive voltage.
Schottky diode voltage limiter:
Schottky diodes are another type of diode that has a lower forward voltage drop compared to standard diodes. This characteristic makes them ideal for fast switching applications and voltage clamping circuits.
In a Schottky diode voltage limiter circuit, the Schottky diode is connected in parallel to the sensitive component. When the input voltage exceeds the forward voltage drop of the Schottky diode (usually around 0.3 to 0.5 volts), the diode starts conducting, providing a low-impedance path for the excess current to flow. This effectively limits the voltage across the sensitive component, protecting it from overvoltage.
Both Zener and Schottky diode voltage limiters offer different characteristics and are chosen based on the specific application requirements. When designing voltage limiters, it's essential to choose diodes with appropriate breakdown voltage (for Zener diodes) or forward voltage drop (for Schottky diodes) to ensure effective protection of the sensitive components. Additionally, other components like resistors may be added to fine-tune the voltage clamping levels and enhance the performance of the voltage limiter circuit.