Optocouplers

Could do if they existed.

- Steve

would that make it an octocoupler?

Cheers Terry

Nice part and I can't think of anything that would be a drop in replacement. Went to all the usual suspects and nothing quite the same. I have always resigned myself to using 2 Sharp PC847 and moving on. The nice thing about them is you can get the PC817 and stack 'em if you need some weird number of isolated ports.

Jim

Thanks, neat part, I looked high and low and didn't find a part with the same pin out. I guess people have been getting on with the other parts for so long no one thought to try a better way for byte wide ports.

Jim

Hello James,

The production manager in my first job always threatened to throw his coffee mug if an engineer even thought about that :-)

--
Regards, Joerg

http://www.analogconsultants.com

Haven't had a mug thrown yet. What statement didn't he like? Using a PC847 or stacking PC817?

Jim

Indeed, someone hereabouts suggested a quad, but I can't find one of those either. The only quad packages have outputs on both sides of the device.

- Steve

Nice one.

:-)

- Steve

Hello James,

Stacking parts was an absolute no-no. For rework maybe, but only grudgingly.

--
Regards, Joerg

http://www.analogconsultants.com

In message , dated Mon, 11 Sep 2006, Terry Given writes

... or even a octopoupler?

-- OOO - Own Opinions Only. Try

and There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

I guess he'd be a bit peeved at me then. Just did a coin op crane board that needed 6 isolated inputs from the mech. Used 1 PC847 and 2 PC817 stacked end to end. Nice thing about the PC8X7 optos is that the higher density parts are just PC817s stuck together in one epoxy package. Now stacked one on top of the other I could understand, but in this case I mean end to end ;).

Jim

Nah, the Sharp PC817 is a quadopto with all the diodes on one side and the transistors on the other.

2 of 'em have been my port isolator of choice for a while now.

Jim

--
The NEC PS2501L-4 is a nice part too.  Surface mount, with the
diodes and outputs on opposite sides.

Go to:

http://www.ncsd.necel.com/opto/index.html

and put PS2501 in the part number search box.

LOL :)

Cheers Terry

Looks like the PC8X7 with a better CTR and I have seen some of the PC8X7 parts NOT meet the min CTR listed in their spec. I'll have to check out a few samples......

Jim

Hello James,

As long as all the pins are on the PCB and you can at least get thick dental floss through the gaps between parts the production folks are usually ok with it ;-)

They just don't like anything that has to be done by hand or needs the skills of a neuro-surgeon to assemble.

--
Regards, Joerg

http://www.analogconsultants.com

I am certain that you won't find a pin compatible alternative to the Isocom device. The best I can suggest is the Sharp PC3Q62 or PC3Q71 but you will need to re-design your pcb layout (if you are using a pcb).

These are completely isolated devices so you need two 16 pin packages to be equivalent to the Isocom device.

These are similar to the TLP521-4 that I have to hand. I also have a couple of ILQ74 devices sat in front of me now, but the internals of those are even worse. (Alt pin pairs are reversed !!!)

The things that made me get so excited about the Isocom part were, commoned devices on both input and output, and 8 in a nice neat line for attaching to an MCU. (That would even be good for veroboard !!) With MCU's so popular now, even more so than when I was playing with D8749H's and 6811's I would have though that this was a logical 'next step'.

As I said further up the thread, I'm using the ULN2803A as a an output driver, and it just fits on the port nicely... why oh why can't I do the same on inputs?

- Steve