Characterization
A TVS diode is characterised by:
- Leakage current: the amount of current conducted when voltage applied is below the maximum reverse standoff voltage.
- Maximum reverse standoff voltage: the voltage below which no significant conduction occurs.
- Breakdown voltage: the voltage at which some specified and significant conduction occurs.
- Clamping voltage: the voltage at which the device will conduct its fully rated current (hundreds to thousands of amperes).
- Parasitic capacitance: The nonconducting diode behaves like a capacitor, which can have a deleterious effect on high-speed signals. Lower capacitance is generally preferred.
- Parasitic inductance: Because the actual overvoltage switching is so fast, the package inductance is the limiting factor for response speed.
- Amount of energy it can absorb: Because the transients are so brief, all of the energy is initially stored internally as heat; a heat sink only affects the time to cool down afterward. Thus, a high-energy TVS must be physically large. If this capacity is too small, the overvoltage will possibly destroy the device and leave the circuit unprotected.
Read more about this topic: Transient-voltage-suppression Diode