I'm trying to determine the date code for an op-amp in a piece of equipment that I think was purchased around 2000.
The chip is an ADI (Analog Devices) OP496GP quad op-amp. I've checked the datasheet and did not find a code reference, and google was unhelpful (including checking links to the ADI website).
Here's the totality of what's on the 14-pin plastic DIP:
ADI S9542
OP496GP
M29604 0
Center line is the chip ID, so either S9542 or M29604 is probably a date code. However, 95 and 96 seem awfully early for a near-2000 production date. Not impossible, perhaps it was old stock when sold. But I'm not sure, so I thought I'd ask here.
The picture found
here (attached for future reference) suggests it's the first line, as I doubt that is an IC from 1946(!)
Usually IC date codes are 4 digits, where the first pair of numbers specify the year and the second pair specifies the week. So without looking at any other references on the net, despite the ease of doing such, I would surmise that S9542 is the date code and that this IC was made in the 42nd week of 1995.
The prefix S might be used to bin the part according to one of the critical parameters (say, offset voltage or current), or to indicate a specific fab or facility, etc.