For Long reliability of optocoupler circuit in which operate mode need to choose.

 

What opto coupler?
There are several types.
Max.

 

hi S.
1st PDF shows some opto-coupler options
2nd PDF some interesting PD applications.
E

 

For Long reliability of optocoupler circuit in which operate mode need to choose.

The most common type of opto is best used within a nfb loop because the transfer curve isn't very linear.

Numerous consumer devices use them as switches so the isolated front panel micro can switch the live side of the SMPSU on & off.

 

For Long reliability of optocoupler circuit in which operate mode need to choose.

As long as the optocoupler is operated well within it's maximum ratings there should be no significant difference in the long term reliability whether it's operated in the linear region or as a switch.

 

What opto coupler?
There are several types.
Max.

Thanks for reply,

I'm using Opto IC ->TLP 291GB CTR(100% to 400%). The following circuit I have used,getting fail after 6 months or later.


MOD:
Attached datasheet.

 

What is the nature of the failure?

 

What is the nature of the failure?

Thanks for reply.

Don't no how it's getting fails.

 

Thanks for reply,

I'm using Opto IC ->TLP 291GB CTR(100% to 400%). The following circuit I have used,getting fail after 6 months or later.
View attachment 150386

MOD:
Attached datasheet.

What is the load?

How much current are you expecting to get through the output side of the opto?

 

Shorting the output when it's on could zap the transistor.

 

What is the nature of the load? If it is at all inductive and there is no protection, then that can shorten the life considerably.

 

Since the GB version of that opto has a CTR specified as 100%, you are operating it right on its limit (input current ~5mA, output current needed for full pull-up = 5mA), with no allowance for load current. That is not a good design.