I was working on a little clock project that runs off a 3v coin battery with the arduino bootloaded at 8MHz until I realized that the ds1307 has a 4.5V minimum. It looks like the 1302 doesn't seem to be similar enough to the 1307, I can't tell if it would still work.
The ds3231 seems to have 3v operation but I can only find it already placed onto a board. Because of this I don't know if the boards are meant for 5v only(they seem to have an entire extra IC so who knows whats going on there). I also don't know if I can interface the IC by itself with the arduino like I can with the 1307. I would really like to have a lone chip, my 3v projects are usually meant to be pretty compact. I don't have any issue with SOIC packages.
Is it a good idea to be using a ds3231 without a breakout board? What is that little extra chip for? Is there something else better to try?