Power Diode types
Power Diode types:
Classification of the signal level diode is NOT the scope of this post.
This post will discuss about the power diode types ONLY.
Based on the reverse recovery characteristics, the power diodes are classified as follows
- General Purpose Diodes
- Fast Recovery Diodes
- Schottky Diode
General Purpose Diodes:
- This kind diodes have high reverse recovery time. It will be in the range of 25μs.
- The diode current rating will be from 1A to several thousand amperes.
- The voltage rating will be from 50V to 5kV. Some of the applications of the general purpose diodes are battery charging circuits, uninterruptible Power Supplies(UPS) and electrical traction etc.
Fast Recovery Diodes:
- As the name indicates, these diodes have very low reverse recovery time. It will be less than 5μs.
- They are mainly used in switching circuits like choppers, commutation circuits, switching mode power supplies etc.
- The current rating of the diode will be from 1A to several thousand amperes.
- The voltage rating will be from 50V to 3kV.
- In this type of diode,
(1) For low voltage ratings ( below 400V), the epitaxial process is used for the diode fabrication.
(2) For diodes having voltage rating above 400V, diffusion technique is used for the fabrication of diodes.
- In high frequency switching circuits like SMPS, the Schottky diodes are used (in those applications we can't use the general purpose diodes).
- In this type of diodes, instead of P-N junction ( semiconductor to semiconductor) metal to semiconductor junctions used.
- The Schottky diodes have very fast recovery time and low forward voltage drop.
- The current flow will be done by only majority carriers.
- So the time delay due to reverse recombination is avoided.
- The drawback with Schottky diode is they have low voltage ratings ( around 100V) and forward current ratings(upto 300A).
You may also like to read:
Thanks for reading about power diode classification .. Please leave your comments below...