Introduction to power semiconductor devices
Power Semiconductor devices:
Fig: Heirachy of Semiconductor
- Power semiconductor diode is the “power level” counter part of the “low power signal diodes” with which most of us have some degree of familiarity.
- Power semiconductor devices are semiconductor devices used as switches or rectifiers in power electronic circuits (switch mode power supplies for example) . They are also called power devices or when used in integrated circuits, called power ICs.
- These power devices, however, are required to carry up to several KA of current under forward bias condition and block up to several KV under reverse biased condition.
- These extreme requirements call for important structural changes in a power diode which significantly affect their operating characteristics.
- These structural modifications are generic in the sense that the same basic modifications are applied to all other low power semiconductor devices (all of which have one or more p-n junctions) to scale up their power capabilities.
- It is, therefore, important to understand the nature and implication of these modifications in relation to the simplest of the power devices, i.e., a power semiconductor diode.