Explain the function of a transient voltage suppressor (TVS) diode.
1 Answer
A Transient Voltage Suppressor (TVS) diode is an electronic component designed to protect sensitive electronic circuits and devices from voltage surges or transients that can occur due to various reasons such as lightning strikes, electrostatic discharge (ESD), inductive load switching, or other sudden changes in the electrical environment. The primary function of a TVS diode is to divert excessive transient voltages away from the protected circuit, thus preventing damage to the circuit components.
The TVS diode works by conducting current when the voltage across its terminals exceeds a certain threshold, which is typically its breakdown voltage. When the voltage surge exceeds this threshold, the TVS diode rapidly switches from a high-resistance state (off state) to a low-resistance state (on state), allowing the excess current to flow through it. This effectively creates a low-impedance path for the transient current, bypassing the sensitive components of the circuit.
There are two common types of TVS diodes:
Avalanche Diodes: These TVS diodes operate in the reverse-biased breakdown region, where a small increase in voltage leads to a large increase in current. When a transient voltage spike occurs, the diode enters the avalanche breakdown region, and the excess energy of the transient is absorbed and dissipated as heat.
Zener Diodes: Zener TVS diodes operate similar to conventional Zener diodes, but they are designed to handle larger transient currents. They operate in the reverse-biased breakdown region, where the voltage remains relatively constant above a certain threshold. This helps maintain a stable clamping voltage during transient events.
Key advantages of using TVS diodes for protection include:
Fast Response: TVS diodes can react to transient events within nanoseconds, providing swift protection to the sensitive components.
Low Clamping Voltage: During the conduction state, TVS diodes maintain a relatively low clamping voltage, ensuring that the protected circuit doesn't experience excessive voltage levels.
Reusability: After the transient event passes, the TVS diode returns to its high-resistance state, ready to protect against the next transient event.
Compact Size: TVS diodes are available in small packages, making them suitable for integration into various circuit designs.
Overall, the transient voltage suppressor diode acts as a sacrificial component that sacrifices itself to protect the main circuit from harmful voltage surges, thus safeguarding sensitive electronics and preventing potential damage.
The TVS diode works by conducting current when the voltage across its terminals exceeds a certain threshold, which is typically its breakdown voltage. When the voltage surge exceeds this threshold, the TVS diode rapidly switches from a high-resistance state (off state) to a low-resistance state (on state), allowing the excess current to flow through it. This effectively creates a low-impedance path for the transient current, bypassing the sensitive components of the circuit.
There are two common types of TVS diodes:
Avalanche Diodes: These TVS diodes operate in the reverse-biased breakdown region, where a small increase in voltage leads to a large increase in current. When a transient voltage spike occurs, the diode enters the avalanche breakdown region, and the excess energy of the transient is absorbed and dissipated as heat.
Zener Diodes: Zener TVS diodes operate similar to conventional Zener diodes, but they are designed to handle larger transient currents. They operate in the reverse-biased breakdown region, where the voltage remains relatively constant above a certain threshold. This helps maintain a stable clamping voltage during transient events.
Key advantages of using TVS diodes for protection include:
Fast Response: TVS diodes can react to transient events within nanoseconds, providing swift protection to the sensitive components.
Low Clamping Voltage: During the conduction state, TVS diodes maintain a relatively low clamping voltage, ensuring that the protected circuit doesn't experience excessive voltage levels.
Reusability: After the transient event passes, the TVS diode returns to its high-resistance state, ready to protect against the next transient event.
Compact Size: TVS diodes are available in small packages, making them suitable for integration into various circuit designs.
Overall, the transient voltage suppressor diode acts as a sacrificial component that sacrifices itself to protect the main circuit from harmful voltage surges, thus safeguarding sensitive electronics and preventing potential damage.