optocouplers are so big...do you know a small one?

F

Flyback

Well-Known Member

• Aug 16, 2014

• #1

Hello
We wish to signal from one micro to three others by opto's or digital isolator's, -we need the isolation because of ground bounce due to the proximity of several high power smps.
So which gives the smallest solution?
Which gives the solution with less sensitivity to higher temperatures?
There is no need for voltage isolation, its just that we are trying to get around the ground bounce

Do you know of any small opto's...they all seem to be at least this big...
https://www.digikey.com/product-detail/en/5962-8876801XA/5962-8876801XA-ND/2347004

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Aug 16, 2014

• #2

Look at Analog Device's icoupler's. You may get more per package.

 

K

KMoffett

Well-Known Member

• Aug 16, 2014

• #3

Google: SOP optocouplers
Go for the 4-lead versions

Ken

 

F

Flyback

Well-Known Member

• Aug 16, 2014

• #4

https://www.vishay.com/docs/83515/tclt1000.pdf
..smaller , but still too big

 

K

KMoffett

Well-Known Member

• Aug 16, 2014

• #5

Check out optocouplers in SOT packages.

Ken

 

K

KMoffett

Well-Known Member

• Aug 16, 2014

• #6

Deleted

Ken

 

K

KMoffett

Well-Known Member

• Aug 16, 2014

• #7

Is this on still too big?: https://www.vishay.com/docs/83446/vom617a.pdf

Ken

Sorry, thought that was an SOT

 

F

Flyback

Well-Known Member

• Aug 16, 2014

• #8

yes its too big, at this rate, we may end up having to go for a ground level translator ic

 

K

KMoffett

Well-Known Member

• Aug 16, 2014

• #9

Smallest I can find: https://www.digikey.com/product-detail/en/VOS618A-2T/VOS618A-2TCT-ND/2813378

What're your space limits? If this is a one-off and the foot print is the factor, could you stack these vertically and jumper to the leads?

Ken

 

crutschow

Well-Known Member

Most Helpful Member

• Aug 16, 2014

• #10

The best solution is to correct the ground scheme so the ground-bounce isn't a problem.
Alternately you could use differential input amplifiers (one input to ground) to minimize any common-mode ground-bounce in the signal.

 

F

Flyback

Well-Known Member

• Aug 16, 2014

• #11

wow, didn't think they came that small, but its still too big....ground level translators sound like the answer....
cant corrct it , at the end of the day theres going to be impedance in those traces.

 

F

Flyback

Well-Known Member

• Aug 16, 2014

• #12

Heres a way to do it small...
https://datasheets.maximintegrated.com/en/ds/MAX14842.pdf
...but why is this the only IC of its kind in the world?

 

T

tarts

New Member

• Sep 17, 2019

• #13

3 years later and heres your answer:

https://www.electronics-articles.co...s-smallest-transistor-output-optocoupler.html

The technology seems to keep up the innovation demand