A Transient Voltage Suppressor (TVS) diode is an electronic component designed to protect sensitive electronic devices and circuits from transient voltage spikes or surges. These voltage spikes can be caused by various factors, such as lightning strikes, electrostatic discharge (ESD), inductive load switching, or other sudden changes in the electrical environment.
The TVS diode is a specialized type of diode that has a fast response time and can conduct excess voltage away from the protected circuit when the voltage exceeds a certain threshold. It operates in a similar way to a regular diode, but with some important differences:
Reverse Breakdown Voltage (Clamping Voltage): The key feature of a TVS diode is its ability to start conducting heavily once the voltage across it reaches a certain threshold known as the reverse breakdown voltage or clamping voltage. This voltage is typically chosen to be slightly above the maximum operating voltage of the device or circuit it's meant to protect.
Fast Response Time: TVS diodes have very low capacitance and are designed to respond rapidly to voltage transients, diverting the excess energy away from the protected circuit before it can cause damage. This fast response time is crucial to ensure that the voltage spike is clamped down quickly.
When a transient voltage spike occurs and the voltage across the TVS diode reaches its clamping voltage, the diode's impedance drops significantly, allowing it to conduct current and provide a low-resistance path for the excess energy to dissipate. This prevents the excessive voltage from reaching and damaging the sensitive components downstream in the circuit.
TVS diodes can come in various forms, such as unidirectional (clamping voltage applies only in one direction) and bidirectional (clamping voltage applies in both directions), depending on the specific application requirements.
In summary, TVS diodes protect electronics by acting as a "safety valve" for voltage spikes. They provide a quick and controlled path for the excess energy to be diverted away from the sensitive components, thereby safeguarding the devices from potentially harmful transient events.