Please help me identify this part

Could someone please help me determine what this part is?

U5 in the images below
Z84B is what it says on the top (90% sure using magnifying glass)





Some background:

The two traces that go to the header connect to the header as you would expect. The header itself connects to an ATX motherboard as a power switch. In other words, the header essentially acts as a momentary switch.

Does anyone know what U5 is? I was thinking maybe an optocouple? Google doesn't help

An optocoupler is actually a very good probability. Can you tell what else is attached to the chip, or are those traces buried in some inner layer? What's the broader context of this device--is it on a multifunction panel, a PCB out of a case, or what?

Mohonri said:

An optocoupler is actually a very good probability. Can you tell what else is attached to the chip, or are those traces buried in some inner layer? What's the broader context of this device--is it on a multifunction panel, a PCB out of a case, or what?

Click to expand...

Judging from what looks like an ATX power connector and LED headers on the board, I'm going to guess it's a motherboard of some sort. Could also be a mini power supply like what some ITX boards use.

SOT353 Package TinyLogic UHS 1-Bit Low Power Bus Switch

I do believe this is the datasheet you're looking for. (Btw, this one was a real pain to find.)

Datasheet Here.

Thanks for the reply. That's the correct part, yes. Unfortunately I had already figured it out, fairchild has a part marking search on their website.

You may be happy to know I replaced the part and all is well....I friggen hate desoldering SMT packages though.