Reverse Voltage Vs Reverse Breakdown Voltage

Thread Starter

Tony9168

Joined Mar 6, 2016
32
Hi Guys,

The reverse voltage in the absolute maximum rating is 3V while the reverse breakdown voltage in the electrical specification is 5V?

I am confused from my understanding, since the absolute maximum rating already stated that the reverse voltage is 3V, how can it be the reverse breakdown voltage in the electrical specification is 5V? (higher than the absolute maximum rating)

Or is there any different between reverse voltage and reverse breakdown voltage?

Could anyone advise?

Thanks.
 

WBahn

Joined Mar 31, 2012
26,398
Is this for an LED? A transistor? What?

What do the notes say?

We are not mind readers.

Could you please provide a link to the data sheet where this is located?
 

WBahn

Joined Mar 31, 2012
26,398
Link of the datasheet: https://www.mouser.com/datasheet/2/678/V02-2456EN_DS_ACNV2601_2017-04-120-1483441.pdf

The reverse voltage is available at page 6 while the reverse breakdown voltage is available at page 7. Please check.
Thanks.

Others (there are several members that are super well versed in LED phenomena and characterization) will probably have more to say, but here is my take in general.

The absolute maximum ratings are values that, if you exceed them, the manufacture is not willing to make any promises that damage, either immediate or long-term, will not occur.

The electrical characteristics are just that -- descriptions of the electrical behavior of the circuit and those descriptions may well involve parameters that are outside the absolute and/or recommended operating region.

When they say that the absolute maximum reverse voltage is 3 V, they are saying that, over the entire operating range, you should not exceed 3 V reverse breakdown otherwise the device may no longer meet spec for one reason or another. It might, but they won't make any promises. Now, the actual reverse voltage that will cause it to no longer meet spec is higher than 3 V (but you don't know how much) and how much higher it is depends on exactly where you are in terms of all of the other parameters, most notably temperature.

Also, there may be multiple failure mechanisms related to operating the device with an excessive reverse voltage with those related to breakdown just being one of them. There could be mechanisms that result in increases stresses at the microcracks that exist in all such structures and that tend to reduce the output efficiency quicker than normal, thus reducing the life expectancy below spec. Imagine taking measurements over all possible combinations of all of the operating conditions and tabulating the reverse voltage that causes it to fall out of spec under each. At some of them it might be 30 V, at others it might be 10 V. Pick the lowest -- say it's 4 V. You then establish an absolute spec at 3 V so that you stay comfortably away from all of them.

Put another way, the manufacturer is saying that as long as you stay below a reverse voltage of 3 V, regardless where you are operating in terms of the other ratings, the device will continue to meet spec.

In this case (look at the note on that line), the reverse breakdown voltage is saying that the reverse voltage at which the reverse current reaches 100 μA will occur no sooner than a reverse voltage of 5 V -- and this is a characterization that is valid at room temperature, not over the entire temperature range). They are not saying that it isn't lower than 5 V at other temperatures, only that it is never lower than 5 V at room temperature.

Since you shouldn't be operating there in the first place (due to the absolute rating), this line probably has little utility to you. But characterizations like this are often part of device models used by simulators and by incorporating it into the device model simulators can often model fairly closely things like the reverse current at lower voltages and allow your designs to take that into account.
 
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