Does the TVS diode have polarity?

How to determine the polarity of TVS diodes in electronic circuits? There are many ways to classify TVS diodes, which can be divided into unipolar and bipolar types according to polarity, commonly known as unidirectional TVS diodes and bidirectional TVS diodes.
Unidirectional TVS diode can only protect against positive or negative pulses, with positive and negative poles, and one end of the cathode wire is the negative pole; When welding, pay attention to the positive and negative electrode directions; The forward characteristics of a unidirectional TVS are the same as those of a voltage regulator diode. Bidirectional TVS diodes have no positive or negative polarity distinction; During welding, one end should be connected to the circuit to be protected and the other end should be grounded; The V-I characteristic curve of a bidirectional TVS is equivalent to two voltage regulator diodes connected in reverse series.
Therefore, regarding the question of "Does TVS diode have polarity?", let's summarize the answer once again. The first step is to confirm whether the TVS is unidirectional or bidirectional. There are many ways to confirm whether the TVS is unidirectional or bidirectional. The most direct method is to check according to the model. The suffix A at the end of the model is unidirectional, and CA is bidirectional. Taking the SMDJ33A and SMDJ33CA supplied by the brand MDD as an example, it can be seen that SMDJ33A is a unidirectional TVS and SMDJ33CA is a bidirectional TVS. Of course, there are slight differences in the naming conventions of TVS models supplied by different brands. If you want to be more precise and direct, you can directly check the product datasheet for detailed parameter information about TVS diodes at a glance. Of course, tools can also be used for detection. The second step is to confirm the polarity of both directions, which also confirms the polarity of both directions. Monopolar TVS has positive and negative poles, while bipolar TVS has no positive or negative polarity. The third step is to pay attention to the positive and negative poles of the unidirectional TVS during welding.