[Introduction] This article introduces the parameter terms and definitions of TVS transient suppression diodes, as well as the minimum and maximum ambient operating temperatures of the device application circuit. The operating temperature must not affect adjacent components, which is a parameter that designers must consider.

Pry equipment

This type of suppressor has “crowding” properties and is typically associated with 4-layer NPNP silicon controlled bipolar devices or plasma gas/GDT devices. Once the threshold or breakover voltage is reached, further increases in current will cause the device to conduct electricity rapidly with a forward voltage drop of only a few volts. In essence, the line will be in a temporary “short circuit” condition when a transient occurs.

Operating temperature range (Tj)

Minimum and maximum ambient operating temperatures for the device’s application circuitry. The operating temperature must not affect adjacent components, which is a parameter that designers must consider.

Capacitance(Cj)

A circuit element property that allows a circuit element to store electric charge. In circuit protection, off-state capacitance is usually measured at a frequency of 1 MHz and a bias voltage of 2 V.

Reverse off-state voltage (VR)

For a unidirectional TVS diode, this is the maximum peak voltage that can be used in the blocking direction without large current flow. For bidirectional transients, it adapts to either direction. Its meaning is the same as the maximum off-state voltage and the maximum operating voltage.

Breakdown voltage (VBR)

Breakdown voltage measured at a specified DC test current, typically 1mA. Usually the maximum and minimum values ​​are stated.

Peak pulse current (IPP)

Maximum pulse current that can be applied repeatedly. If specified, it can usually be a 10×1000μs double exponential waveform or 8×20μs.

Maximum clamping voltage (VC)

The maximum voltage that can be measured from the protector when the maximum peak pulse current occurs.

Peak pulse power (PPP)

Expressed in watts or kilowatts, the 1ms exponential transient value (see Figure 1 on page 23) is the product of IPP and VCL.

Reverse off-state voltage (VR)

The equipment VR should be at or above the peak operating level of the circuit (or part of the circuit) to be protected. This is to ensure that the TVS suppression diodes do not suppress the circuit drive voltage.

Peak pulse current (IPP)

Peak pulse current (IPP) determines the maximum current that a TVS diode can handle without being damaged. The required IPP must be the peak transient voltage divided by the source impedance. Note: TVS diodes fail in the event of a short circuit; if a TVS diode fails due to a transient, it will still protect the circuit.

Maximum clamping voltage (VC)

It is the peak voltage that will appear in the transient suppression diode when encountering the peak pulse current (IPP) based on the 10X1000us exponential waveform. The VC value of each TVS diode is specified in the electrical characteristics table in each series of data sheets.

Check environmental working parameters

Ensure that the actual applied voltage is less than or equal to the device’s off-state voltage and that the operating temperature is within the device’s specified range.

More information

You can view more general TVS diode information through the following methods: https://semiware.com/. If you have technical questions, please contact our technical support engineers: fae01@semiware.com.

About Semiware

Semiware has a comprehensive product lineup of overvoltage protection device families. The company leverages its technology in the semiconductor field and application background in end products to serve customers in the electronics, automotive and industrial markets. For more information, please visit semiware official website: https://semiware.com