TVS diode in ESD Protection : Working & Key Advantages

Introduction : Electrostatic discharge (ESD) can damage sensitive electronics in an instant. Transient Voltage Suppressor (TVS) diodes offer rapid protection by clamping voltage spikes and diverting harmful current away from vulnerable components. This application note describes how TVS diodes operate and the key advantages they provide for reliable, rugged circuits under ESD stress.

TVS diode based ESD Protection Circuit Working

The circuit below is used for protecting sensitive components with the help of TVS diode.

The figure-1 depicts one such voltage suppressor circuit.

• Under normal operation, TVS diode remains OFF.
• When voltage exceeds breakdown threshold, TVS diode conduct heavily, which clamps voltage to safe level.

The figure-2 is also ESD protection circuit used by human beings for testing ICs. There are different human body models each with different voltage sensitivities as mentioned below in table-1.

Following table-2 mentions design safety margins.

Advantages of TVS diode

Following are some of the benefits of TVS diode.

1. It responds extremely quickly to voltage transients to clamp spikes before they harm sensitive components.
2. These diodes can absorb large surge currents which make them suitable for lightning transients, ESD and inductive switching spikes.
3. TVS diodes limit excessive voltage to a clamped level very close to safe limit for protected circuit. This reduces chance of damage due to over voltage.
4. After transient event is over, TVS diodes return to their non-conducting state automatically. There is no manual reset needed.
5. As they are available in both unidirectional and bidirectional configurations, they offer protection for circuits where polarity of spikes may vary.

Conclusion: TVS diodes are among the most crucial protection devices for guarding electronic circuits against voltage transients and ESD events.