Optocouplers. I'm looking for an alternative to the Isocom CSM170. I only want a handful and they are talking in MOQ terms of 1000 pcs :-(
It appears to be the holy grail of opto/layout solutions for a micro controller port. I'm surprised there isn't anything out there... or is there ?
MTIA,
- Steve
What's that ?
Graham
I went to
Jim
The clue was in the title, but take a look here:-
- Steve
Hello Steve,
While a multi-opto is nice it is IMHO not the holy grail if Digikey doesn't carry it and you can't get low qties anywhere. Maybe you could look at 4-ch versions that are more available. NEC, Toshiba etc.
Hello Jim,
It's here:
4ch is clearly a step in the right direction, but if you want to optoisolate a whole port at once then the CSM170 would be a lovely chip to use. I'm currently using a 6N137, which means one chip per pin. Obviously a pin to pin layout would make life oh so much easier for layout purposes. Afterall, I have an 8ch driver in the ULN2803A on the output port, so something to match on the other side of the MCU would be perfect.
- Steve
try
- Steve
Hello Steve,
The 137 is a good device. I used the CNW137 wide body version a lot.
Sure. But I try to stay away from boutique parts. They may offer a really elegant solution and then bite you from behind. For example when the purchasing manager shows up in your office all red in the face because his buyers can't get any.
Depending on what is transmitted there may be other options. I like LAN transformers for isolated transfers. Of course, then you need Schmitts on the other side and you may have to nudge them into a start position after system turn-on if needed.
I gather that much but someone else had already tried to find it and failed.
Ok. So what's the problem ?
Graham
It's a 8 opto package.
- Steve
Absolutely..!
I was chatting with one of our engineers, and he agreed that seems an obvious part when you think about it. I'm surprised that the bigger companies have never made such a thing.
The main reason I need opto's, is because I'm using 24V throughout the rest of the kit (hence the 2803) with photocells and limit switches on inputs and pneumatic valves on the outputs, all in a very noisy environment, a factory !
Ho hum... looks like the two quads I have sitting in front of me are going to get designed in instead.
- Steve
And ?
Graham
It's 18 pin.
- Steve
Really ?
I'm actually asking him to get to the point ! Something that didn't happen 'til recently.
Graham
And you want 8 couplers in one package ?
If it's a DIL package you're currently using, why not use a couple of SMD quads instead ?
Graham
I figured that, I'm just playing with him now...
- Steve
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