5 COMMON QUESTIONS ABOUT DIOTEC TVS DIODES ANSWERED

Before we begin discussing Diotec TVS Diodes, we assume that you already know about the basics of diodes. If not, there is no problem at all! We can quickly define what a diode is or if you want to know more, you may read through this article here – All You Need To Know About Diotec Diodes

A diode is a two-terminal electronic component where the current is always polarized, and its flow is only possible in one direction. The diode terminals are named Anode for the positive (+ and Cathode for the negative (-). The diode current flow starts from the Anode down to the Cathode and never the other way around. 

Now that we explained and recalled what a diode is, we will be more specific as we discuss one of its kind. Diotec Semiconductor receives high recognition for it, which is the TVS diodes. 

What is a TVS diode? 

A TVS Diode stands for ‘Transient, Transil, or Thyrector Voltage Suppression.’ An electronic component protects devices from sudden voltage spikes from the connected spikes.  

Diotec TVS diodes are part of the different DIOTEC products available for distinct market sectors worldwide. Those DIOTEC’s are made of silicon that significantly contributes to the protection for voltages that suddenly increase beyond the desired level. 

When there is a parallel circuit connection, Diotec TVS diodes have a protective path around them (refer to Fig. 1, Fig. 2). 

Under normal conditions, these diodes create a low electrical resistance when the input voltage is within the limit. The excess energy is delivered directly to the ground, so the circuit operation is not affected and can continuously function normally.  

diotec-tvs-diodes

 

Image Source | Diotec Semiconductor

How Can We Protect A TVS diode?

All DIOTEC products have various choices being offered to consumers by diodes suppliers. There are two main types of TVS diodes known, the Unidirectional and the Bidirectional. These types correlate with how Diotec TVS diodes are protected, which concerns their internal composition. 

Unidirectional TVS diodes behave asymmetrically to protect one polarity from potential surging. The signals for the opposite polarity work similarly with a standard rectifier.

On the other hand, Bidirectional TVS diodes are for applications that need protection on both the Anode and Cathode terminals. Unlike Unidirectional, this diode behaves symmetrically to block off the excess energy from both polarities.  

How to Choose The Most Suitable Diotec TVS Diodes?

We have been discussing sudden voltage surges, a typical environment for diodes. The first thing you need to know is the maximum level of current a device would require. 

Different parameters are being used when selecting a diode, and the most common are as follows:

Reverse Voltage. This parameter sets to be above the highest possible current flow across the diode when turned off.

On the other hand, the following parameters may be used when a diode is turned on:

Forward Current – This is the opposite of Reverse Voltage, and the only difference is that the diode is turned on.  

Forward Voltage – Last but not least, this parameter is when the small voltage drop in the forward direction has to be equal to or below a specific value. 

Again, these are just a few parameter examples, and there are other factors to consider to obtain the correct diode. For example, if you visit DIOTEC stores, representatives will present you with options that differ according to their voltage range. In addition, you may read through the table below, which is a datasheet parameter exclusively provided by DIOTEC suppliers to customers.

DIOTEC TVS Diodes Parameters 

PPPM
The Peak Pulse Power Dissipation measures the diode’s ability to dissipate energy and is defined as the peak pulse current IPPM multiplied by the maximum clamping voltage VC. Because surges are time-dependent, transient phenomena, PPPM is specified with a pulse current of 10/1000 µs: 10 µs rise to a peak and 1000 µs exponential decay to the one-half height. For non-repetitive pulses, the peak power must stay below the curve.
VWM
The Stand-off Voltage is the maximum specified voltage at which the TVS diode operates in high impedance mode without entering into the breakdown.
VBR
The Breakdown Voltage is the value at which the TVS device will start conducting. VBR is specified at a fixed current level and is usually ca. 10% higher than VWM.
VC
The Maximum Clamping Voltage defines the voltage across the TVS diode at maximum current IPPM. The below formula applies: PPPM= IPPM x VC

Selecting the correct Diotec TVS diodes can be complicated, so it is best to reach out to experts.

DIOTEC suppliers like BD Electronics would be able to assist you on this wherever you are in the world.

What causes Diotec TVS diodes to fail?

There are unfortunate events where TVS diodes may fail even after choosing the most appropriate according to the device’s voltage range. There are three failure modes identified: Shorts, Open, and Degraded devices. 

A Short TVS Diode is the most common where the device’s resistance value is lower than one at a DC voltage of 0.1 V (ref. ANSI/IEEE C62.35). As a result, the device will conduct a certain amount of operating current towards the ground, depending on the resistance in the line ahead. This situation may refer to the available current from the power supply source in its power line application. 

The second is an Open TVS Diode characterized by a breakdown voltage VBR greater than 150 % of the pretested value at an applied test current (lP) (Ref. ANSI/IEEE C62.35). The unit must be taken out of the circuit and tested on a curve tracer to verify its condition. 

There may be instances that a TVS diode can encounter both short and open failure modes at the same time when the circuit is improperly fused. 

Lastly, the most difficult to detect is the Degraded TVS Diodes. This mode takes place when there is a stand-by current beyond the maximum.

An example would be with a power bus line where the current level reaches the maximum or when the unit shorts from the conduction increase of the electric current.  

Diotec TVS Diodes Supplier

You may already be overwhelmed with all the information, but they are essential if you want to start your journey with diodes. Multiple DIOTEC suppliers across the globe can help you if reading is too much for you to take. For example, if you are from Europe, you may consider BD Electronics, one of the authorized distributors of DIOTEC Semiconductor.

For BD Electronics’ assistance on the different DIOTEC products, you may reach out through the following channel.

Related News

Get a Quote

We’d love to hear from you, get in touch with us.

BD Electronics LTD.