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.
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?
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.
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.