Basics about Semiconductor and Power Device
Wednesday, April 22, 2020
Edit
Difference between Insulator, Semiconductor & Conductor
 |
| Difference |
What is Power Device?
High doping concentration makes the device as power device, Additional n-drift layer is present in every power device, Thickness of this layer depends on breakdown voltage of the device .
Heavily doped layers decides current rating while lightly doped layers decides voltage rating.
 |
| Power devices |
Thyristors are a class of power semiconductor devices having 4-layers of alternating p- and n-material. It acts as a open or closed switch, due to this reason, they are used frequently in control applications. Thyristor is a general name given to family of power devices SCR(Silicon controlled rectifier) & TRIAC(Triode for AC) are used for high power applications. Other devices are used for low power applications.
 |
| Some Thyristor Family member |
The concept of 4-layer devices is usually shown in below figure as an equivalent circuit of a pnp and an npn transistor.
These devices would conduct,when it is forward biased, if there is sufficient leakage current in the upper pnp transistor, it can act as base current to the lower npn device and hence both transistors into will comes in saturation region.
 |
| 4-Layer Device |
