The Transient Voltage Suppressor diode (or TVS Diode) is an easy and fast-acting protection diode, designed to protect electronic circuits against transients and overvoltage threats. While TVS diodes can be either bidirectional or unidirectional making them slightly more expensive than their other diode counterparts.
Graph courtesy of TI Training
When selecting TVS Diodes there are some important parameters to be considered. These are:
• Reverse Standoff Voltage (VR)- This is the maximum voltage the power line will be able to handle.
• Maximum Clamping Voltage (VC max)- This is the lowest voltage your circuit needs to operate.
• Capacitance- TVS diodes add some capacitance to the circuit they are protecting.
For example, if two diodes have the same amount of current, but have less clamping voltage. You will also see a reduction in power dissipated and dynamic resistance (or slope resistance post breakdown).