Common Cathode Diodes: Safe to Use in Parallel?

In summary, using two diodes in parallel is not a good idea because you will have run away current. If you need 6A current, you can use something like this.
  • #1
DragonPetter
830
1
I know that using diodes in parallel is generally a bad design practice since you will have run away current in one of the diodes since they are not necessarily matched exactly.

But is it safe to use diodes in parallel if they're designed as a common cathode part?

this is an example:
http://www.onsemi.com/pub_link/Collateral/MBRD620CT-D.PDF

So is it safe for me to use the 2 diodes in the package in parallel?

Thank you
 
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  • #2
Why would you want to use two diodes in parallel? If you need 6A current use something like this:

http://www.vishay.com/docs/94252/94252.pdf

If you just happen to have some of the product you mentioned on hand and want to use them for a prototype it will likely work fine, but if you are designing something, use a single diode.

Fish
 
  • #3
Why would you want to use two diodes in parallel? If you need 6A current use something like this:

http://www.vishay.com/docs/94252/94252.pdf

If you just happen to have some of the product you mentioned on hand and want to use them for a prototype it will likely work fine, but if you are designing something, use a single diode.

Fish
 
  • #4
DragonPetter said:
I know that using diodes in parallel is generally a bad design practice since you will have run away current in one of the diodes since they are not necessarily matched exactly.

But is it safe to use diodes in parallel if they're designed as a common cathode part?

this is an example:
http://www.onsemi.com/pub_link/Collateral/MBRD620CT-D.PDF

So is it safe for me to use the 2 diodes in the package in parallel?

Thank you

Diodes on a common IC can be assumed to be very well matched, so you could put them in parallel.

There won't be any "run-away current" anyway. the problem would be that the diodes would not share the current equally if they were mismatched.

The ratings for this device look optimistic, though.
It is about 0.25 inches square and drops 0.9 volts at 6 amps. That is 5.4 watts.

It is going to get very hot. Hot enough to burn a 0.25 inch square in your fingertip if you touch it.
 

Related to Common Cathode Diodes: Safe to Use in Parallel?

1. What are common cathode diodes?

Common cathode diodes are electronic components that allow current to flow in only one direction. They have two terminals, an anode and a cathode, and are used in circuits to control the direction of current flow.

2. Is it safe to use common cathode diodes in parallel?

Yes, it is safe to use common cathode diodes in parallel as long as they have the same specifications and are properly connected. This means that the anode of one diode should be connected to the anode of the other diode and the cathodes should be connected together.

3. What are the benefits of using common cathode diodes in parallel?

Using common cathode diodes in parallel allows for higher current carrying capacity and better heat dissipation. This is because the diodes share the current load and distribute the heat generated more evenly.

4. Can different types of common cathode diodes be used in parallel?

No, it is not recommended to use different types of common cathode diodes in parallel. This is because they may have different voltage and current ratings, which can lead to unequal sharing of current and potential damage to the diodes.

5. Are there any precautions to take when using common cathode diodes in parallel?

Yes, it is important to ensure that the diodes are properly connected and that the current is evenly distributed between them. It is also recommended to use diodes with the same specifications to avoid potential damage. Additionally, proper heat dissipation measures should be taken to prevent overheating.

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