Greetings, group. I'm trying to identify a surface mount device on some boards I'm repairing, but not having much luck.
The device is a small black plastic rectangular surface-mount device, about 1.5mm x 2.5mm in size.
The pins are in a 5-pin DIP arrangement (basically a 6-pin DIP with pin 5 missing, leaving just pins 1,2,3,4,6).
The markings on the device include "T1|3", where I'm assuming the third character is a vertical bar, though it's possible it might be an upper-case letter "i", or a lower-case letter "L". There's a band on the pins 1/6 end, and 3 small square marks near pins 2,3,5.
I'm assuming this is some sort of IC rather than a discrete component, because the board manufacturer has designated it "U22" (rather than, say, "Q22" or "D22").
Functionally, it seems to be processing a signal and feeding it into the input side of an optoisolator, which then gets fed to a microprocessor.
Any clues on what this is, or how to go about finding out? Searching Google, Arrow, Mouser, Digikey have proven unfruitful. I'm stumped.
(Nope, I can't ask the board manufacturer about it; they consider that "proprietary information". Basically I'm trying to "reverse engineer" the board and make a partial schematic of it.)