Transient Voltage Suppression (TVS) Diode

Introduction

Transient voltage suppression diode is a type of avalanche diode which protects the circuit from high voltage surges. This diode may be either unidirectional or bidirectional. Unidirectional TVS (Transient voltage suppression) diode operates similar to avalanche diode, as it acts as a rectifier in forward bias & surge protector in reverse bias. Bidirectional TVS diode acts as two avalanche diodes opposing each other in series. TVS diode provides a fast response high withstand capability, long life and low capacitance. TVS diode is a P-N junction diode that is placed in parallel with the circuit should not get damage. TVS diodes have three key voltage ratings named as reverse standoff voltage, breakdown voltage and clamping voltage. During normal operation with the circuit at or below the diode’s reverse standoff voltage, the diode does not conduct and its low leakage current and low capacitance male virtually transparent to the circuit when an over voltage event occurs and voltage begins to rise in the circuit the TVS diode enters breakdown and shunts the incoming current to ground.

Characteristics of Transient Voltage Suppression Diode

TVS diode is tuned to combine a fast response time with low breakdown and clamping voltages relative to its reverse standoff voltage, meaning transients can be clamped quicker and closer to the normal operating voltage. The diodes are manufactured with large area P-N junctions that the area P-N junction area can repeatedly carry high currents and withstand high transient voltages ensuring reliable operation and longer life. This construction also results in low capacitance which allows the TVS diodes to be used on high speed data lines without distorting the signal.

Applications