Most of the engineers recommend not to use parallel diodes for the greater power. But I can see many TO-220 diodes which have two diodes in parallel internally. How can I understand?

 

Hi Willen, can you provide an example? Having two diodes in a single die (or single TO220 package) is very common. Generally they share a common cathode or common anode. A common application would be a full wave rectifier circuit using a transformer with a CT (Center Tap). Take a look at this link. Scroll down to the first full wave rectifier circuit example. Two diodes which could easily be in a single die with a common cathode.

Note the diodes are not exactly in parallel but share either a common anode or cathode. Thus three legs.

Ron

 

Most of the engineers recommend not to use parallel diodes for the greater power. But I can see many TO-220 diodes which have two diodes in parallel internally. How can I understand?

Do you have a part number for reference?

Diodes that are manufactured on the same substrate can be designed for good matching. The same can't be said for discrete diodes; even ones from the same batch.

 

They are used in Switchmode psus, for ease of packaging..

 

Even though the two diodes in the package could be connected in parallel, they normally aren't, but are used as part of a full-wave rectifier or bridge.