What is the difference between single and bidirectional transient suppression diodes

What is the difference between single and bidirectional transient suppression diodes

Transient suppression diode are directional, unidirectional and bidirectional, so how to distinguish the transient suppression diode direction?

The simple and intuitive method is to look at the surface of the component, such as a cathode wire on it, which is a unipolar TVS tube, unidirectional, otherwise it is bidirectional; You can also look at the model, the SM830A and SM8S30CA mentioned above, it can be seen that the A after the suffix of the model represents unidirectional, CA represents bidirectional. Of course, it is also possible to test by checking the product manual and borrowing a multimeter!

What is the difference between single and bidirectional transient suppression diodes?

1. The current curve is different: the forward characteristics of the unidirectional TVS tube are the same as those of ordinary voltage regulator tubes, and the reverse is a PN avalanche device; Both the forward and reverse sides of the bidirectional TVS tube are PN avalanche devices.

2. The junction capacitance is different: the junction capacitance of unidirectional TVS is larger than that of bidirectional TVS.

3. Different applications: unidirectional TVS is generally used in DC circuits, and two-way TVS is generally used in AC circuits.